Usage describes the way a language is used by native speakers, it is the application of grammar rules at a local level. English usage varies from region to region in multiple ways including word choice, syntax, spelling and the use of idioms.
Grammar and usage are inextricably linked. Grammar is a system of rules that dictates multiple ways in which sentences may be composed. Usage is the preferred way native speakers compose their sentences, within the rules of grammar. Usage changes quickly, driven by necessity, etiquette, expediency and whim. Sometimes, usage defies grammar. If a certain type of usage becomes widespread and entrenched in the language, it will eventually become part of the system of rules known as grammar.
English is a living language, proved by its ever-changing usage. Grammarist is here to explain the language we use today that is virtually unchanged for hundreds of years, as well as the newly coined language of today.
-
- -able and -ible
- -esque
É
- Épée, foil or sabre
À
- à la carte
A
- A hold vs ahold
- A la (à la)
- A leg up
- A lot vs allot
- A miss is as good as a mile
- A or an
- A priori
- A stone's throw
- A whole nother
- a.m. and p.m.
- Abandon vs. abandonment
- Abdicate, abnegate, abrogate
- Abided vs. abode
- Ability vs. capability vs. capacity
- Abject vs object
- Abjure vs. adjure
- Abolishment vs. abolition
- Aborted vs. abortive
- Abracadabra
- Absolve vs resolve
- Abstruse vs. obtuse
- Accell
- Access
- Access vs excess
- Accidental vs occidental
- Acclimate, acclimatise, acclimatize
- Acclimation vs acclamation
- Accord vs. accordance
- Achilles' heel
- Acme vs acne
- Acquaintanceship
- Acronym vs anacronym
- Acute vs chronic
- Ad hoc
- Ad hominem (usage)
- Ad infinitum
- Ad nauseam
- Ad-lib and ad lib
- Adapt vs adopt
- Adaptable or adaptive
- Adaption vs. adaptation
- Addicting vs. addictive
- Addiction vs. dependence
- Addition vs. edition
- Addlepated, addlebrained and addleheaded
- Adduce vs educe
- Adjudicate
- Administrate
- Admission vs. admittance
- Adolescence vs adolescents
- Adopted vs. adoptive
- Advance vs. advanced
- Advent
- Adverse vs. averse
- Advert vs. avert
- Advice vs. advise
- Aegis
- Aerie vs airy
- Aerobic vs anaerobic
- Aeroplane vs. airplane
- Aesthetic vs. ascetic
- Aetiology or etiology
- Affective vs. effective
- Affinity vs infinity
- Afflict vs. inflict
- African-American vs. black
- Afterward vs. afterwards
- Afterward vs. afterword
- Aggravate
- Aggravate vs aggregate
- Aggravate vs mitigate
- Aggression vs. aggressiveness
- Agnostic vs. atheist
- Agree
- Ahold
- Ailment vs aliment
- Ain't
- Alas
- Albeit
- Alcoholism vs dipsomania
- Algorithm vs logarithm
- Alimentary vs elementary
- All but
- All but vs anything but vs everything but
- All of a sudden or all of the sudden
- All right vs. alright
- All that
- All-around, all-round
- Allegation vs accusation
- Alleviate vs elevate
- Alligator vs. crocodile
- Alliterate, literate or illiterate
- Alliteration vs assonance
- Allude vs. elude
- Allusion vs. elusion vs. illusion
- Allusive, elusive or illusive
- Alphabetic vs. alphabetical
- Alter ego
- Alternate vs. alternative
- Alternately vs alternatively
- Although vs. though
- Alumna, alumnae, alumni, alumnus
- Always vs all ways
- Amalgam vs. amalgamation
- Amative or amatory
- Amazeballs
- Amber vs ember
- Ambiguous vs ambivalent
- Ameliorate vs alleviate
- Amend vs. emend
- American
- American Indian vs Native American
- Amiable vs. amicable
- Among vs. amongst
- Among vs. between
- Amoral vs. immoral
- Amount vs. number
- Ampersand
- Amuse vs. bemuse
- An historic
- Analogue vs. analogy
- Anamorphic
- Anathema
- Ancillary vs auxiliary
- And yet
- Anecdote vs antidote
- Angel vs angle
- Animal adjectives
- Animal collective nouns
- Animate vs adamant
- Annal vs annual
- Annual, perennial or biennial
- Anomalous vs anonymous
- Another think coming
- Antennae vs. antennas
- Antichrist
- Antlers vs horns
- Anyone or any one
- Anyplace
- Anyway vs. anyways
- Apartment and flat
- Ape vs. monkey
- Apiary vs aviary
- Apocryphal vs canonical
- Apologetics
- Apoplectic vs apocalyptic
- Apostle
- Apotheosis
- Apposite vs opposite
- Appraise vs. apprise
- Apprehend vs apprehensive
- Apprehend vs comprehend
- Apprehensive vs reprehensive
- Approbation vs opprobrium
- Appropriate vs. expropriate
- April Fool's or April Fools'
- Apropos
- Argot vs ergot
- Argumentative vs. argumentive
- Arise or rise
- Around the clock, round the clock
- Around vs. round
- Arouse vs. rouse
- Arrant vs. errant
- Arse vs. ass
- Artesian vs artisan
- As crook as Rookwood
- As far as
- As per
- As thick as thieves
- As yet, as of yet
- Ascared
- Ascent vs. assent
- Ascent, ascendance, ascendancy, etc.
- Ascribe vs attribute
- Ascribe vs subscribe
- Askew vs eschew
- Aspersion vs dispersion
- Asphalt, cement, concrete, pavement
- Aspiration vs inspiration
- Aspire vs inspire
- Assail vs. assault
- Assent vs. consent
- Assume vs. presume
- Assure, ensure, insure
- Astrology vs astronomy
- Asylum
- At a loose end
- At loggerheads
- At the end of the day
- Atlas
- Attain vs. obtain
- Attend to vs. tend to
- Au contraire
- Au pair
- Aught
- August
- Auspicious vs suspicious
- Authoritative vs. authoritive
- Autobiography vs biography
- Autocorrect
- Autotune or Auto-Tune
- Autumn vs. fall
- Avail
- Avant-garde
- Avenge vs. revenge
- Avocation vs. vocation
- Aw or awe
- Await vs wait
- Award vs reward
- Away vs a way
- Awfully
- Awry vs wry
- Axiom, adage or epigram
B
- Baby blues
- Back in the day
- Back up vs. backup
- Backward vs backwards
- Backwater or backwaters
- Bacteria vs virus
- Bad penny
- Bad rap vs. bad wrap
- Bae vs bay
- Bald-faced vs. boldface
- Balmy vs. barmy
- Baloney vs. bologna
- Bamboozle
- Ban vs. bar
- Band (together) vs. bandy (about)
- Bar mitzvah and bat mitzvah
- Barnstorm
- Basis (on a daily basis, on a regular basis, etc.)
- Bastion
- Bathos vs pathos
- Baton vs batten
- Batten the hatches
- Bawdy vs body
- Bawl out
- Bazaar vs. bizarre
- Be patient or have patience
- Bear market, bull market, bearish, bullish
- Beat around the bush
- Beeline
- Beg the question (usage)
- Beggar belief
- Begrudge
- Behalf
- Behest vs bequest
- Belated
- Belay vs belie
- Belie
- Bellwether
- Bellyache
- Benchmark
- Benefactor vs patron
- Bereaved vs. bereft
- Beside or besides
- Betwixt
- Beyond the pale
- Bezel vs embezzle
- Biannual vs. biennial
- Biannual, biennial and semiannual
- Biceps and triceps
- Bid, bade, bidden
- Big-ups
- Bimonthly and semimonthly
- Binded vs. bound
- Binge-watch
- Bingo
- Bisect vs dissect
- Bisexual or pansexual
- Bit vs. bitten
- Bitter pill to swallow and hard pill to swallow
- Biweekly vs semiweekly
- Black market
- Black out vs blackout
- Blackmail vs extortion
- Blandish vs brandish
- Blatant vs. flagrant
- Blather vs blabber
- Blather vs. blither
- Blench vs blanch
- Bling
- Blond vs. blonde
- Bloviate
- Blowhard and windbag
- Blue blood
- Blue collar, white collar
- Bobbsey twins
- Bodega
- Boggle the mind and mind-boggling
- Bohemian
- Bona fide, bona fides
- Bone of contention
- Bone to pick
- Bone vs debone
- Bonhomie
- Boondoggle
- Boot camp
- Botanic vs. botanical
- Boughten
- Bound vs. bounded
- Bounteous vs bountiful
- Bourgeois, bourgeoisie
- Braid vs abrade
- Brainchild
- Brand spanking new
- Brandish vs brand
- Breach, breech, broach
- Breath vs. breadth (vs. width)
- Bric-a-brac and knick-knack
- Bridle vs. bridal
- Bring vs take
- Briton
- Broach vs. brooch
- Bromance
- Bromide
- Brung, brang
- Buck naked, butt naked
- Buffer vs. buffet
- Build up vs. buildup
- Bullion vs boullion
- Bullseye or bull's eye
- Bully pulpit
- Bum-rush vs bum's rush
- Bumpkin
- Bunk, bunkum, buncombe
- Bunny vs Bunnie
- Burgle vs. burglarize
- Burned vs. burnt
- Burnish vs tarnish
- Burnout vs. burn out
- Bursted
- Burthen
- Busybody
- But vs. yet
- Butt heads and bump heads
- Butter wouldn't melt in his mouth
- Butterfingers
- Buzzword
- By and by vs. by the by
- By dint of
- Byproduct
- Bête noire
C
- C'est la vie
- Cacao vs. cocoa
- Cache vs. cachet
- Cacti vs. cactuses
- Caduceus vs staff of Asclepius
- Call it a day and call it a night
- Callous vs. callus
- Calvary vs. cavalry
- Calves vs. calfs
- Can goods or canned goods
- Can of worms vs pandora's box
- Can vs may
- Can't vs cant
- Canard
- Canary in the coalmine
- Candy corn
- Cannot or can not
- Cannot see the forest for the trees
- Canny vs uncanny
- Cantankerous
- Canvas vs. canvass
- Capital vs. capitol
- Capitulate vs recapitulate
- Capstone, keystone or cornerstone
- Captivate vs capture
- Car park vs parking lot
- Caramel vs carmel
- Carbon copy
- Card shark vs. card sharp
- Careen vs. career
- Caretaker vs caregiver
- Carnation vs incarnation
- Carnivore, herbivore or omnivore
- Carrot, carat, karat, caret
- Carte blanche
- Cartography
- Casket vs coffin
- Cassandra
- Cast the first stone
- Caste vs cast
- Casted
- Castigate vs castrate
- Catch-22
- Cattle vs chattel
- Catty-corner, kitty-corner
- Cauterize vs cauterise
- Cavalcade
- Cavalier
- Caveat
- Cease and desist
- Cease and surcease
- Cede vs. concede
- Celebrant or celebrator
- Celiac or coeliac
- Celiac vs celeraic
- Center around or center on
- Centrifugal vs. centripetal
- Centrifuge vs. subterfuge
- Centuries
- Ceremonial vs ceremonious
- Certainty vs. certitude
- Chafe vs. chaff
- Chain letter
- Chaise lounge and chaise longue
- Chalk up vs. chock
- Champing at the bit vs. chomping at the bit
- Character or caricature
- Charade and charades
- Charism vs charisma
- Charlatan
- Charnel house
- Chasten vs. chastise
- Cheek by jowl
- Cheek to cheek vs cheek-to-cheek
- Childish vs. childlike
- Chills down the spine
- Chimera
- Chink vs. kink
- Chinwag
- Chips vs. fries
- Choate or inchoate
- Chock-full
- Chopper vs. copter
- Chortle
- Chose vs choose
- Cisgender vs transgender
- Cistern vs sister
- Civil rights and human rights
- Clamor vs clamber
- Classic vs. classical
- Clean vs. cleanse
- Cleanup vs. clean up
- Cleave
- Clench vs. clinch
- Client vs. customer
- Cliffhanger
- Cliffs Notes
- Climactic vs. climatic
- Clone
- Closer vs closure
- Cloture vs closure
- Cloying and mawkish
- Co-op vs. co-opt
- Cockamamie
- Coddle and mollycoddle
- Cognate and false cognate
- Coiffure vs coiffeur
- Cold-call
- Collaborate vs corroborate
- Collectible vs collectable
- College vs. university
- Collegial vs. collegiate
- Collision vs collusion
- Coma vs comma
- Comb-over
- Come over vs overcome
- Come-hither look
- Comedienne
- Comestible vs combustible
- Comic vs. comical
- Comity vs comedy
- Commencement
- Commend vs command
- Commentator vs. commenter
- Commiserate vs commensurate
- Compared to or compared with
- Compel vs. impel
- Complacent vs complicit
- Complacent vs. complaisant
- Complement vs. compliment
- Compose vs. comprise
- Comprise vs compromise
- Compunction vs compulsion
- Concave vs. convex
- Conceive vs. perceive
- Concerning
- Concerted
- Conches vs. conchs
- Concurrent vs consecutive
- Condemn vs. condone
- Confidant vs. confidante
- Confirmation bias
- Conflate vs conflagrate
- Conflict of interest
- Congruent vs. congruous
- Connect the dots and join the dots
- Connive vs contrive
- Connote vs. denote
- Conscience, conscious and self-conscious
- Consequential vs consensual
- Conservatory, solarium or sunroom
- Consolation vs constellation
- Conspiracy or collusion
- Contaminate vs contaminant
- Contemporaneous vs. contemporary
- Contemptible vs. contemptuous
- Content or contented
- Contiguous vs continuous
- Continental breakfast
- Contingency vs contingent
- Continual vs. continuous
- Contravene vs contradict
- Contronym and auto-antonym
- Conundrum
- Conversate
- Convivial vs congenial
- Convocation, commencement or invocation
- Coon's age
- Coop, coup or coupe
- Cooties
- Copyright vs. copywrite
- Core, corps and corpse
- Cornet vs. coronet
- Corollary vs. correlation
- Corroborate vs cooperate
- Cosmetology vs. cosmology
- Cosset vs corset
- Costed
- Cottage industry
- Couch-surf
- Could care less
- Could have, could've or could of
- Counsel vs consul
- Coup de grace
- Coups vs coos
- Cover all the bases
- Covert vs overt
- Covet vs covert
- Crackerjack
- Crapshoot
- Crave vs craven
- Crayfish, crawfish, crawdad, etc.
- Crayon vs Crayola
- Cream of the crop
- Creature comfort
- Credible vs. credulous
- Credible, creditable or credulous
- Creeped vs. crept
- Crevasse vs. crevice
- Crews vs cruise
- Crick (variant of creek)
- Criteria, criterion
- Cronyism
- Cross vs crucifix
- Crowdsourcing vs crowdfunding
- Cruciferous
- Cryptid
- Crèche and manger
- Cue vs. queue
- Cul-de-sac
- Culpable vs liable
- Cum
- Curmudgeon
- Currently
- Curriculum vitae vs résumé
- Cursive vs coercive
- Cursory vs curse
- Custom vs costume
- Cut and dried
- Cut off your nose to spite your face
- Cut the mustard
- Cut to the chase
- Cut-throat
- Cute as a button
- Cyclist vs. biker
- Cynical
D
- D'oh
- Damp squib
- Dampen, damper, dampener
- Dance on someone's grave
- Daresay
- Dark horse
- Data
- Davy Jones's locker
- Day in age (day and age)
- Daylight Saving Time or British Summer Time
- Days vs daze
- De facto
- De rigueur
- Deaf vs deft
- Dealt vs. dealed
- Dearth
- Debark or disembark
- Debauchery
- Decathlon, heptathlon, pentathlon, triathlon and biathlon
- Deceptively
- Decidedly
- Decimate
- Decisive vs divisive
- Deconstruction
- Decrepit vs deprecate
- Decry vs. descry
- Decussate vs desiccate
- Deduce vs. induce
- Deduct vs deduce
- Deep-seeded vs. deep-seated
- Defenestration
- Definite vs definitive
- Defuse vs. diffuse
- Deign
- Delegate vs relegate
- Delude vs dilute
- Delusions of grandeur
- Democracy vs republic
- Demon vs daemon
- Demur vs. demure
- Denounce vs. renounce
- Dent vs dint
- Depose vs dispose
- Deposition vs disposition
- Depository vs. repository
- Depravation vs deprivation
- Deprecate vs. depreciate
- Depute vs dispute
- Derision vs decision
- Descendant vs. descendent
- Desert vs dessert
- Desolate vs destitute
- Desperate vs disparate
- Despite vs. in spite of
- Destroy vs. destruct
- Deteriorate vs decline
- Detract vs. distract
- Device vs. devise
- Devil vs bedevil
- Dharma and karma
- Dialectal vs. dialectical
- Diamond in the rough
- Diaspora
- Dice vs. die
- Dichotomy vs discrepancy
- Dichotomy vs paradox
- Dickensian
- Didactic vs pedantic
- Dieresis and diaeresis
- Difference vs deference
- Different from, different than, different to
- Diktat
- Dilapidated
- Dilemma
- Directional words
- Dirigible or blimp
- Disabuse, misuse and abuse
- Disassemble vs. dissemble
- Disburse vs. disperse
- Discomfit vs. discomfort
- Disconnect
- Discrete vs. discreet
- Disenfranchise vs. disfranchise
- Disillusion vs. dissolution
- Disinterested vs. uninterested
- Disparity vs disparateness
- Dispense with vs. dispose of
- Disposed vs. predisposed
- Dissociate vs. disassociate
- Distaff
- Distinct vs. distinctive
- Distrust vs. mistrust
- Divers vs. diverse
- Divorcée, divorcé, divorcee
- Do apologize
- Docent
- Dog days
- Dogged vs dogged
- Doggerel
- Dominant vs predominant
- Don't look a gift horse in the mouth
- Don't's or don'ts
- Doodle
- Doomsday vs Domesday
- Doppelgänger
- Dos or do's
- Dossier
- Dotage vs senility
- Dotard
- Double entendre
- Double jeopardy
- Double vs. redouble
- Double whammy vs whammy
- Double-edged sword
- Doubtlessly
- Dove vs. dived
- Down the pike vs. down the pipe
- Downfall vs. downside
- Downplay or play down
- Downright vs outright
- Doyen or doyenne vs docent
- Dragged vs. drug
- Draw a line in the sand
- Dreamed vs. dreamt
- Dredge vs drudge
- Dregs vs dredge
- Dribble vs. drivel
- Dribs and drabs
- Drier vs. dryer
- Drink drank drunk
- Drink the Kool-Aid
- Drive-by
- Droll
- Drop off vs. drop-off (vs. dropoff)
- Drop-dead vs drop dead!
- Dry goods
- Du jour
- Dudgeon vs dungeon
- Due to vs because of
- Duly noted
- Duly vs dully
- Dumb down
- Dumb waiter and dumbwaiter
- Duplicate vs duplicity
- Duplicate vs replicate
- During the course of
- Dwarfs vs. dwarves
- Dwelled vs. dwelt
- Dyed in the wool
- Dystopia or utopia
- Déjà vu
E
- E.g. vs. i.e.
- Each other vs. one another
- Earmark
- Earnest vs Ernest
- Earthy vs. earthly
- Earworm
- Easter egg
- Ecclesiastical and ecclesiastic
- Eclipses vs ellipsis
- Economic vs. economical
- Economics vs. finance
- Effable vs affable
- Eggnog
- Egregious vs gregarious
- Either vs ether
- Either vs neither
- Elbow grease
- Elder, eldest
- Electric, electrical, electronic
- Elegy vs. eulogy
- Eleventh hour
- Elfs vs. elves
- Elocution vs. locution
- Embolization and embolisation
- Emeritus
- Emigrate vs. immigrate
- Eminent vs. immanent vs. imminent
- Emission vs omission
- Emolument vs emollient
- Empathetic vs. empathic
- Empathy vs. sympathy
- Empire vs umpire
- En route
- En vogue, in vogue
- Endear
- Endeavor vs. endeavour
- Endemic vs. epidemic
- Endorphin
- Enervate vs energize
- Enervate vs. innervate
- England, Great Britain, United Kingdom
- Enjoin vs join
- Enormity vs. enormousness
- Ensconce vs sconce
- Enthuse
- Entitled vs. titled
- Entomology vs. etymology
- Entree vs entrée
- Envision vs. envisage
- Epic vs epoch
- Epicenter
- Epidemic vs pandemic
- Epidemic vs pandemic
- Epigram vs. epigraph
- Epiphany or Twelfth Night
- Epitaph vs epithet
- Epithet vs sobriquet
- Epitome vs epiphany
- Eponymous
- Equable, equatable, equitable
- Equator vs prime meridian
- Equinox vs solstice
- Equivalence vs. equivalency
- Equivocate vs prevaricate
- Ergo
- Ergonomics
- Erratum, addendum and corrigendum
- Ersatz
- Erupt vs irrupt
- Especially vs specially
- Espouse vs expound
- Espresso vs. expresso
- Estimate vs. estimation
- Et al.
- Et cetera (etc.)
- Ethereal vs ephemeral
- Ethics vs. morals
- Ethnic vs ethic
- Ethnicity vs. race
- Evacuate
- Evade vs invade
- Even keel
- Everyday vs. every day
- Everyone vs every one
- Evoke vs. invoke
- Ex post facto
- Exacerbate vs exasperate
- Exalt vs. exult
- Exceed vs accede
- Excited vs exited
- Excoriate vs execrate
- Excrete vs secrete
- Exculpate vs exonerate
- Exemplary
- Exercise vs. exorcise
- Exhibit vs. exhibition
- Exhort vs extort
- Existent vs. extant
- Existential
- Expatriate vs immigrant
- Expectant vs. expecting
- Expedient vs expeditious
- Expedite vs expedient
- Expiration date and expiry date
- Explicate vs expletive
- Explicit vs implicit
- Expose vs exposé
- Expound vs expand
- Extant vs extent
- Extemporaneous
- Extradite vs expedite
- Extraordinaire
- Extricate vs extirpate
- Exuberant vs exorbitant
F
- Factious vs fractious
- Factoid
- Fail vs flunk
- Fain vs. feign
- Fair vs. fare
- Fairy-tale ending
- Fait accompli
- Faker vs fakir
- Fallow vs follow
- Falsehood, falsity, falseness
- Fame vs defame
- Famous, infamous and notorious
- Far East, Middle East, Near East
- Faraway vs far away
- Farther vs. further
- Fastly
- Fatal vs fateful
- Fatuous vs facetious
- Faux
- Faux pas
- Fay, fey
- Faze vs. phase
- Fearful vs. fearsome
- Feckless vs reckless
- Feminity vs. femininity
- Ferret out
- Fervent vs. fervid
- Festivus
- Fete
- Fewer vs. less
- Fiancé vs. fiancée
- Fiction vs. nonfiction
- Fictional vs. fictitious
- Fiefdom
- Fifth column
- Figurehead
- Filet vs. fillet
- Filibuster
- Financer vs. financier
- Finger-licking good
- Firefight
- Firefly and lightning bug
- Fireplace vs hearth
- Firing line vs. line of fire
- First aid
- First floor
- First World problem
- First-world, third-world
- Firsthand and secondhand vs first-hand and second-hand
- Firstly, secondly, thirdly, etc.
- Fish vs. fishes
- Fit vs. fitted
- Flagellants vs flatulence
- Flair vs. flare
- Flammable vs. inflammable
- Flash in the pan
- Flat out
- Flaunt vs. flout
- Flautist vs. flutist
- Flesh out vs. flush out
- Fleshly vs. fleshy
- Flied
- Flip one's lid vs. flip one's wig
- Flora and fauna
- Flotsam and jetsam
- Flounder vs. founder
- Flummox
- Fluorescent vs incandescent
- Fly-by-night
- Fodder vs father
- Folderol
- Foley
- Follow up, follow-up, followup
- Font vs fount
- Food coma
- Fool's errand
- Foolproof vs. full-proof
- Foot long
- Football fields
- For heaven's sake
- For the purpose of
- For, four and fore
- Fora vs. forums
- Forbear vs. forebear
- Forbidding vs. foreboding
- Force majeure
- Forceful vs forcible
- Forecast vs. forecasted
- Forego vs. forgo
- Formally vs formerly
- Former, latter
- Formulas vs formulae
- Fortnight
- Fortuitous vs. fortunate
- Fosbury flop
- Fox guarding the hen house
- Fractious vs fracas
- Fractious vs fraction
- Franken-
- Frankenstein's monster
- Frankincense and myrrh
- Fraud or defraud
- Fraught
- Frenemy
- Freudian slip
- Fritter away
- Frivolity vs. frivolousness
- Full stop vs. period
- Full-fledged, fully fledged
- Fulsome
- Funereal
- Fungi vs. funguses
- Funner, funnest
- Fur vs fir
- Furlough
- Furor vs. furore
- Fusillade vs fuselage
- Fusion vs confusion
- Futz vs putz
G
- Gadfly
- Gaff vs. gaffe
- Gallimaufry
- Gallon vs galleon
- Gallop vs Gallup
- Gambit
- Gamut vs gambit
- Gantlet vs. gauntlet
- Gargle vs. gurgle
- Gargoyle or grotesque
- Garner vs garnish
- Garnish vs garnishee
- Garret vs garrote
- Gases vs. gasses
- Gaslighting
- Gavel-to-gavel
- Gay
- Gender vs engender
- Gender vs. sex
- Gentle vs genteel
- Gentrification
- Geographic vs geographical
- German vs germane
- Gerrymander
- Gesture vs jester
- Get down to brass tacks
- Get hitched
- Get religion
- Getaway vs get away
- Ghost vs ghoul
- Gibberish
- Gibe, jibe, jive
- Gift (as a verb)
- Gild the lily
- Gimlet eye and gimlet cocktail
- Gleam vs glean
- Glib
- Glitch
- Glom onto
- Go down a treat
- Go for the jugular
- Gobsmacked
- Gobsmacked
- Godspeed
- Goes without saying
- Goldbrick
- Golden ticket
- Gonna
- Good vs well
- Goodly
- Goose-step
- Got vs. gotten
- Gourmet vs gourmand
- Governance vs. government
- Graffiti
- Grammar vs. usage
- Grandfather (as a verb)
- Grateful vs. gratified
- Gratis, gratuitous and gratuity
- Gravid vs grave
- Great Scott!
- Gregarious vs garrulous
- Grenadine vs grenade
- Grieve vs aggrieve
- Grill vs. grille
- Grinch
- Grinded
- Grok
- Gross vs net
- Ground zero
- Grub
- Gruel vs grueling
- Guarantee vs guaranty
- Gumption
- Guyline vs guideline
- Gymnasia vs. gymnasiums
H
- Habeas corpus
- Habit vs habitat
- Hail vs. hale
- Hairy vs. harry
- Half-mast vs. half-staff
- Halitosis
- Halve
- Hand-me-down
- Hand-wash
- Handful, handfuls
- Handicap vs. handicapped
- Hands down
- Hangar vs. hanger
- Hangdog
- Hanged vs. hung
- Hanker vs hunker
- Hanky-panky
- Happenstance
- Happy camper
- Harbinger
- Hardy vs. hearty
- Hare vs. rabbit
- Harridan and harpy
- Hash out, thrash out
- Haste makes waste
- Hat trick
- Hatemonger and hate-mongering
- Haughty vs hottie
- Hawk vs. hock
- Hay vs straw
- Haymaker
- Heads up
- Healthful vs. healthy
- Hear vs listen
- Heavens to Murgatroyd
- Hector
- Heebie-jeebies
- Helpless vs hapless
- Helter skelter or helter-skelter
- Hence
- Henpeck
- Herbivorous vs herbaceous
- Heretofore or hitherto
- Heroin vs. heroine
- Heterogeneous vs. heterogenous
- Hew vs. hue
- Heyday
- Hie
- Hieratic
- Hieroglyph vs hierograph
- High five
- High on the hog
- Hijinks or high jinks
- Hippocratic vs hypocritical
- Hippogriff or griffin
- Hippopotami, hippopotamuses, hippos
- Historic vs. historical
- Histrionic, histrionics
- Hoax
- Hocus-pocus
- Hokey-pokey, hokey-cokey and hokey-tokey
- Hold my beer
- Hold someone's feet to the fire
- Hold sway
- Holier-than-thou
- Holly vs holy
- Homely vs. homey
- Homily vs sermon
- Homo sapiens
- Homogenous vs. homogeneous
- Homonym
- Homophones, homographs, and homonyms
- Honcho
- Hoodwink
- Hoopla
- Hoover vs. vacuum
- Hooves or hoofs
- Hoping vs hopping
- Horn of plenty and cornucopia
- Horticulturist vs arborist
- Hot spot or hotspot
- How's it going
- Hubris
- Human vs humane
- Humblebrag
- Humorousness
- Hunt-and-peck
- Hunter-gatherer
- Hurrah, hooray, hurray
- Hurricane, typhoon and cyclone
- Hush puppy, hushpuppy or hush-puppy
- Hustle and side hustle
- Hybrid vs highbred
- Hygge
- Hyper- vs hypo-
- Hyperbole
- Hyphen, en dash or em dash
I
- I rest my case
- Iconoclast vs heretic
- Idea vs. ideal
- Ideation vs idea
- Ideologue
- Ides of March
- Idiom vs colloquialism
- Idiot savant or savant syndrome
- If you will
- Ignominious vs ignoble
- Illegible vs. unreadable
- Imaginary or imaginative
- Imbibe vs imbue
- Imitate vs emulate
- Imitate vs intimate
- Imitate vs intimidate
- Immaculate Conception vs. virgin birth
- Immolate vs emulate
- Immunity vs. impunity
- Impair vs impede
- Impassable vs. impassible
- Impassive vs. passive
- Impending vs. pending
- Impends vs impinge
- Imperial vs empirical
- Imperious vs. impervious
- Impetus vs emphasis
- Impinge vs. infringe
- Implosion vs explosion
- Imply vs. infer
- Impractical vs impracticable
- Imprecation vs implication
- Impromptu or improvised
- Impudent vs imprudent
- Impugn vs. impute
- In a manner of speaking
- In due course or in due time
- In excess of
- In kind
- In point of fact or in fact or as a matter of fact
- In terms of
- In the affirmative
- In the course of
- In the midst of
- In the offing
- In the process of
- In the throes of
- Inalienable vs. unalienable
- Incarnation vs incarceration
- Incase or encase
- Incentivize, incent
- Incipient or inchoate
- Incipient vs. insipient (vs. insipid)
- Include, exclude or occlude
- Incommunicado
- Incomparable vs. uncomparable
- Incredible vs. incredulous
- Incubus, succubus
- Indeterminate vs indeterminable
- Indexes vs. indices
- Indian corn
- Indian summer
- Indiscriminate vs undiscriminating
- Indubitably vs undoubtedly
- Inequality vs. inequity
- Inequity vs. iniquity
- Inexplicable vs. unexplainable
- Infect vs. infest
- Infectious vs contagious
- Inference vs interference
- Inflict vs inflect
- Infomercial
- Infraction vs infarction
- Infuse vs suffuse
- Ingenious vs. ingenuous
- Ingrate vs ingratiate
- Inhabit vs habituate
- Inherent vs inherit
- Innate vs enate
- Innocuous vs inoculate
- Inpatient or outpatient
- Inroad vs inroads
- Inside baseball
- Insidious vs invidious
- Insolent vs insolvent
- Insolent vs insulate
- Instantly vs. instantaneously
- Instigate vs incite
- Instigate vs investigate
- Instill vs install
- Instinctive vs. instinctual
- Intellectual property
- Inter-, intra-
- Interment vs. internment
- Intern vs inter
- Internal vs eternal
- Internal vs infernal
- Interpretative vs. interpretive
- Interview with Abed Elmansur
- Inure vs enure
- Invaluable vs. valuable
- Inveigh vs inveigle
- Invention vs intervention
- Inventive vs innovative
- Inveterate vs invertebrate
- Inviolable vs inviolate
- Invite (as a noun)
- Ipso facto
- Irk
- Ironic
- Ironical
- Irregardless
- It's not rocket science
- Itchy feet
- Iteration
- Ivy League
J
- Jack-in-the-box
- Jack-o’-lantern and Halloween lantern
- Jackalope
- Jackanapes
- Jaded
- Jalousie window vs louvre window
- Jam vs. jamb
- Janus-faced
- Jaywalking
- Je ne sais quoi
- Jealousy vs envy
- Jejune
- Jersey vs guernsey
- Jet lag
- Jig vs gig
- Jiggery-pokery
- Jilt vs gilt
- Jingle vs jangle
- Jingoism
- Jolly Roger
- Jones
- Joshing
- Joyful and joyous
- Judicial vs. judicious
- Juggalo
- Juggernaut
- Junction vs. juncture
- Jury-rig, jerry-rig, jerry-built
- Juvenile vs juvenal
- Juxtapose
K
- Kakistocracy
- Kibosh
- Kick the can down the road
- Kick-start
- Kin vs ken
- King's X
- Kith and kin
- Kleenex vs tissue
- Knee-high to a grasshopper
- Knee-jerk, kneejerk
- Kneeled vs knelt
- Knighted vs benighted
- Knit vs. knitted
- Knock up
- Knuckle sandwich
- Kowtow
L
- Lagniappe
- Laird vs lord
- Laissez-faire
- Lambaste
- Lanyard
- Lassitude, lethargy and languor
- Latchkey kid and latchkey child
- Later vs latter
- Latitude vs longitude
- Latter vs ladder
- Laudable vs. laudatory
- Laughing stock
- Laundry list
- Lava vs magma
- Lay vs. lie
- Lazy Susan
- Lead vs. lede
- Learnings
- Leery vs leary
- Leeway
- Legal tender
- Legislator vs legislature
- Lend vs. loan
- Lended vs. lent
- Lessen vs lesson
- Lest
- Leviathan
- Liable vs libel
- Libel vs. slander
- Lie or lye
- Lighted vs. lit
- Like gangbusters
- Limbo
- Limelight vs spotlight
- Lip-sync and lip-synch
- Lipid vs limpid
- Liter or litre vs litter
- Literally vs. figuratively
- Litmus test
- Little to no or little to none
- Lo, lo and behold
- Lock out vs lockout
- Log in vs. log on
- Logo
- Lonely vs. lonesome
- Long in the tooth
- Long johns vs union suit and combination suit
- Longetivity vs. longevity
- Loose vs. lose
- Lorem Ipsum
- Lose the plot
- Lothario
- Lots of vs a lot of
- Lowlife
- Lucid vs lucent
- Lumber vs lumbar
- Luminary vs luminaria
- Lustful vs. lusty
- Luxuriant vs. luxurious
M
- Macabre
- Macaron vs. macaroon
- Machine gun vs. machine-gun
- Maddening vs. madding
- Magical realism
- Magnate vs. magnet
- Magnum opus
- Make do vs. make due
- Make hay
- Makeup, make-up or make up
- Maleficent vs. malevolent
- Malfeasance, misfeasance and nonfeasance
- Manic vs maniac
- Many vs. much
- Marginalize or marginalise vs minimize or minimise
- Marinade vs. marinate
- Marsala vs masala
- Massage vs message
- Masterful vs. masterly
- Materiel vs. material
- Matriculate vs graduate
- Matter of fact or matter-of-fact
- Matter of fact vs fact of the matter
- Maudlin vs modeling or modelling
- Maul vs. mull
- Maundy Thursday
- Maverick
- Maxima vs. maximums
- May be or maybe
- McGuffin
- Mea culpa
- Mealy-mouthed
- Mean vs mien
- Means
- Media vs. mediums
- Mediator vs. moderator
- Melted vs. molten
- Meme
- Memento mori
- Mendacity vs mendicity
- Meretricious vs meritorious
- Meritorious vs maritorious
- Merry Christmas vs Happy Christmas
- Meta
- Metaphor
- Meteoroid, meteor, meteorite (and meteoric)
- Methinks
- Mexican standoff
- Mic drop
- Mice vs. mouses
- Micro- vs macro-
- Microfinance, microcredit and microloan
- Might vs mite
- Milieu
- Minima vs. minimums
- Minimum vs minimal
- Minutia, minutiae
- Misinformed vs. uninformed
- Misogyny and misandry
- Misology vs mixology
- Mixtape
- Mob justice and mob rule
- Mob or demob
- Modern
- Modus operandi (m.o, MO)
- Mogul
- Mojo
- Molotov cocktail
- Momentarily
- Money-grabbing vs. money-grubbing
- Montage
- Moonlight
- Moonshine
- Moot vs. mute
- Moral vs morale
- Morality vs mortality
- Morays vs. mores
- Morbid vs moribund
- Moreso
- Mortar board
- Motive vs motif
- Mouthfuls
- Movable feast
- Mowed vs. mown
- Mr., Mrs., Ms. and Miss
- Muchly
- Muckamuck, mucky-muck and muckety-muck
- Muckraking
- Mumbo jumbo
- Murderers' row
- Myriad
N
- Namby-pamby
- Namesake
- Nary a
- Naught vs. nought
- Nauseating vs. nauseous
- Naval vs. navel
- Ne'er-do-well
- Nebula vs nebulous
- Neck and neck
- Necropsy and autopsy
- Necrosis
- Needle vs nettle
- Nefarious
- Negative prefixes
- Nepotism
- Nest egg
- NGO vs GMO
- Nickname
- Niggle
- Night owl or early bird
- Nip in the bud
- Nitty-gritty
- No-brainer
- Noble vs ignoble
- Noblesse oblige
- Nocturnal vs diurnal
- Noisome vs noisy
- Nomenclature
- Non sequitur
- Nonplussed
- Nonprofit vs. not-for-profit (vs. non-profit)
- Normalcy vs. normality
- Nosy Parker
- Not hardly
- Not un-
- Notwithstanding
- Noxious vs obnoxious
- Nullify
- Number vs numeral
- Numinous vs luminous
- Nunchucks
O
- O vs. oh
- Object lesson
- Obliged vs. obligated
- Oblique
- Obsequious
- Observance vs. observation
- Obsolescent vs. obsolete
- Obstreperous
- Octopi vs. octopuses
- Odious vs odorous
- Oeuvre
- Off of
- Off the cuff
- Off-kilter and out of kilter
- Offhand
- Oftentimes
- Oh well
- Old Glory
- Old hat
- Oligarchy vs monarchy
- Olive branch
- Omnibus vs ombudsman
- On accident vs by accident
- On cloud nine
- On steroids
- On tenterhooks
- On the fritz
- On the lam
- On the up and up
- On the wagon, off the wagon
- Onboard vs. on board
- Once bitten, twice shy
- Once in a lifetime vs once-in-a-lifetime
- One and the same, one in the same
- One fell swoop
- One-hit wonder
- Oompa Loompa
- Oppress, repress, suppress
- Oracle vs auricle
- Oral vs. verbal
- Ordinance vs. ordnance
- Orientate
- Ouster
- Out and out
- Out of pocket
- Out of the blue vs out of the woodwork
- Outset vs onset
- Outside of
- Outsource
- Overlook vs look over
- Overly
- Overnight vs. over night
- Overrate vs overate
- Oversee vs overlook
- Overtake, take over and takeover
- Overthink vs think over
- Overtones vs. undertones
- Oxymorons
P
- Paddy wagon
- Paean, paeon, peon
- Pall vs. pallor
- Palpable vs palatable
- Pander vs ponder
- Panhandle
- Par excellence
- Parade float
- Parallel vs perpendicular
- Paralympics
- Parameter vs perimeter
- Paramount vs. tantamount
- Parentheses vs brackets
- Pariah vs piranha
- Parlay vs. parley
- Parlor or parlour
- Parody vs parity
- Parricide vs. patricide
- Part and parcel
- Pass muster
- Pass the buck, the buck stops
- Passed vs. past
- Past master
- Pastiche vs pistachio
- Pastime vs past time
- Pathetic vs apathetic
- Patois
- Patriotism vs nationalism
- Paucity
- Pay the piper
- Payback vs. pay back
- Peace of mind, piece of (one's) mind
- Peaceable vs. peaceful
- Peccadillo
- Pecking order
- Pedal vs. peddle vs. petal
- Pediment vs impediment
- Pejorative
- Penal vs. penile
- Penchant vs pension
- Pendant vs. pendent
- Penny-pinching
- Pentimento vs pimento or pimiento
- Penultimate
- People vs. persons
- Peplum vs pablum
- Per diem
- Per se
- Perchance
- Peremptory vs pre-emptory
- Perfect storm
- Perfunctory vs peremptory
- Periodic vs. periodical
- Peripatetic
- Perjury
- Perk vs perq
- Permit vs permit
- Pernickety vs. persnickety
- Perpetrate vs perpetuate
- Perquisite vs. prerequisite (vs. requisite)
- Persecute vs. prosecute
- Persona non grata
- Personage vs parsonage
- Personal vs personable
- Personal vs personnel
- Personification vs anthropomorphism
- Perspective vs. prospective
- Peruse
- Pervert vs subvert
- Pet peeve
- Pet vs. petted
- Peter out
- Petrifaction vs. petrification
- Petroglyph vs pictograph
- Pettifogger
- Petulant vs impetuous
- Phenomena, phenomenon
- Phial vs. vial (vs. vile)
- Phony vs. phoney
- Phosphene
- Photogenic vs photographic
- Picaresque vs. picturesque
- Piebald, skewbald, pinto or paint
- Pied Piper
- Piggy bank
- Piggyback
- Pincer vs. pincher
- Pink slip
- Piping hot
- Pissant
- Pitchblende
- Pitcher vs picture
- Pith vs pit
- Placate vs placket
- Place card vs placard
- Plain vs. plane
- Plainclothes
- Plaintiff vs defendant
- Plaintive vs plaintiff
- Plaque vs plack
- Play by ear
- Pleaded vs. pled
- Plenary vs preliminary
- Plenitude vs. plentitude
- Plethora
- Plug-ugly vs pug-ugly
- Plutocrat vs autocrat
- Podium vs lectern
- Poetry vs prose
- Pogrom vs genocide
- Point in time
- Point of view, standpoint, viewpoint
- Point-blank
- Poisonous vs venomous
- Polemic vs. polemical
- Politics
- Polka dot
- Polygamy vs. polygyny vs. polyandry
- Ponderous
- Ponzi scheme and Ponzi game
- Poo vs. pooh
- Poor sport, sore loser and sore winner
- Pop culture
- Popinjay
- Poppycock
- Porch vs veranda or verandah
- Port vs. starboard
- Portend vs pretend
- Portend vs. portent
- Poseur vs poser
- Possibility vs probability
- Poster child
- Potentiality
- Practicable vs. practical
- Practical joke
- Pragmatism
- Praise vs preys
- Pram, baby carriage and baby buggy
- Prank call or crank call
- Precede vs. proceed
- Precedence vs precedents
- Precipitate vs precipitous
- Precocious vs precious
- Predict vs predicate
- Predominantly and predominately
- Premier vs. premiere
- Preposition vs. proposition
- Prescient vs present
- Prescribe vs. proscribe
- Preserve vs persevere
- Presumptive vs. presumptuous
- Pretentious vs portentous
- Preternatural vs supernatural
- Previous vs. prior
- Primal scream
- Private eye and gumshoe
- Proactive
- Problematic vs. problematical
- Procrastinate
- Prodigal and prodigy
- Prodigal son
- Progeny vs prodigy
- Proliferate vs profligate
- Prom and The Proms
- Promise vs premise
- Prone, prostrate, supine
- Proof is in the pudding
- Prophecy vs. prophesy
- Propitiate vs expiate
- Proportional vs. proportionate
- Proprietary vs propitiatory
- Prorogue vs prolong
- Prostate vs. prostrate
- Protagonist, antagonist
- Protean vs protein
- Protégé
- Proved vs. proven
- Proverb vs adage
- Proverbial vs figurative
- Providence vs province
- Province vs provenance
- Psalter vs salter
- Pseudo
- Psych vs. psyche
- Psychiatry vs. psychology
- Psychopath vs. sociopath
- Pull strings
- Pull the rug out from under
- Pullout, pull-out, pull out
- Punctilious vs punctual
- Pundit
- Puppy love or poppy love
- Purple prose
- Purpose vs porpoise
- Purposely vs. purposefully
- Pushing up daisies
- Put on heirs or airs
- Put one's best foot forward
- Put though the wringer vs put through the ringer
- Putative vs punitive
Q
- Quackery
- Qualitative vs. qualitive
- Qualitative, quantitative
- Qualm vs calm
- Quantitative vs. quantitive
- Quantum
- Quash vs. squash
- Quasi
- Quay
- Quelch vs. squelch
- Query vs inquiry
- Quid pro quo
- Quixotic
R
- Rack vs. wrack
- Raconteur
- Radical
- Raise vs rise
- Raison d'etre
- Ramshackle
- Rapt vs. wrapt
- Raring to
- Rational or rationale
- Ravaging vs. ravishing
- Raven vs ravenous
- Razzle-dazzle and razzmatazz
- Razzmatazz or razzamatazz
- Reactionary vs. reactive
- Realty vs reality
- Rearranging the deck chairs on the Titanic
- Rebuke vs refute
- Rebus
- Rebut vs refute
- Receipt vs recipe
- Recur vs. reoccur
- Recuse vs excuse
- Red herring
- Red tape
- Red-letter day
- Redact vs retract
- Redneck vs hick vs hillbilly
- Redress vs readdress
- Reed vs read
- Reforested wood
- Refugee vs immigrant
- Regard vs. regards
- Regime vs. regimen
- Regimen vs regiment
- Regrettable vs. regretful
- Regulate vs relegate
- Reindeer or caribou
- Rejig vs. rejigger
- Relevance vs. relevancy
- Reluctant vs reticent
- Repair vs reparation
- Repatriation vs reputation
- Repel vs. repulse
- Repetitive vs redundant
- Repudiate and refudiate
- Repudiate vs refute
- Repugnant vs pungent
- Repute vs refute
- Reputedly vs reportedly
- Requiem
- Resemble vs reassemble
- Resilience vs. resiliency
- Resolve vs solve
- Respective, respectively
- Restitution vs retribution
- Restrict vs constrict
- Retard
- Retrograde vs anterograde or antegrade
- Retronym
- Retrospect vs introspect
- Reverent vs reverend
- Ridded
- Rife vs. ripe
- Riff vs. rift
- Riffraff
- Riffraff vs riprap
- Right-of-way
- Righten
- Rigor mortis
- Riptide, rip current or undertow
- Risky vs risqué
- Road rage
- Robot, android or droid
- Roll up one's sleeves
- Rollout vs. roll out
- Rollover vs. roll over
- Roman-à-clef
- Roofs vs. rooves
- Rookie
- Root vs. route vs. rout
- Rot vs wrought
- Rotate or revolve
- Rotund vs rotunda
- Round robin
- Roux, rue or roué
- Royal "we"
- Rule of thumb
- Rummy
- Runaway vs. run away
- Running on empty and running on fumes
- Résumé
S
- Sabbatical vs sabbath
- Sadism, masochism and sadomasochism
- Safe-deposit box
- Said
- Said the actress to the bishop
- Salacious
- Salubrious vs lugubrious
- Salvage vs selvage or selvedge
- Samovar vs scimitar
- Sanatorium vs sanatarium
- Sanctimonious vs sanctify
- Sang froid
- Sang vs sung
- Sanguine vs exsanguinate
- Sank vs. sunk
- Sans
- Sarcasm
- Sarcophagus vs mausoleum
- Sari vs sorry
- Sartorial vs satirical
- Satire vs satyr
- Satisficing vs satisfying
- Savant vs servant
- Savvy
- Sawed vs sod
- Say one's peace vs piece
- Scared vs scarred
- Scarfs vs. scarves
- Scatological
- Scavenger hunt
- Scavenger, scavenge
- Schadenfreude
- Schadenfreude
- Schmooze and shmooze
- Scion
- Scissors
- Screed
- Scrimp vs skimp
- Scrip vs script
- Scrooge
- Scrumdiddlyumptious
- Scuffle
- Sculpture vs sculptor
- Seasonable vs seasonal
- Secede vs. succeed
- Second that emotion or notion or motion
- Second-guess
- Secret Santa
- Secret vs. secretive
- Secular vs sacred
- Security blanket
- Sediment vs sentiment
- Sedimentary vs sedentary
- Sedition vs sedation
- Seldomly
- Self-quarantine vs self-isolation
- Seminal
- Sensual vs. sensuous
- Sentience vs sapience
- Sentient vs sentiment
- Separate vs separate
- Sepulcher, crypt, catacomb or mausoleum
- Sequacious
- Sequins vs sequence
- Series
- Serif vs seraph
- Serigraph vs lithograph
- Service (as a verb)
- Serviette or napkin
- Servitude vs certitude
- Sever vs severe
- Shaggy-dog story
- Shall vs. will
- Shame vs ashamed
- Shard or sherd
- Share and share alike vs per stirpes
- Shat vs. shitted
- Shaved vs. shaven
- Sheath vs. sheathe
- Shed vs. shedded
- Shelf vs. shelve
- Shell out
- Shenanigans
- Shill vs chill
- Shined vs. shone
- Shiplap
- Shop till you drop
- Shopping cart or buggy
- Shore vs sure
- Short shrift
- Shotgun vs rifle
- Should have, should've or should of
- Shoveled/shoveling vs. shovelled/shovelling
- Showboat
- Sic
- Sic vs. sick
- Sign up vs signup
- Significant other
- Silva vs silver
- Silver lining
- Silviculture
- Simile
- Sine qua non
- Sisyphean, Promethean or Herculean
- Sit vs set
- Sitting on a powder keg
- Skein vs scan
- Skunkworks
- Slam dunk
- Slap-happy
- Slayed or slew
- Sledge vs sludge
- Sleight of hand
- Slipshod
- Slumgullion and goulash
- Smart alec and smart aleck
- Smite, smote, smitten
- Smithereens
- Smoothe, smoothen
- Smorgasbord
- Snake oil, snake-oil salesman
- Snark
- Sneaked vs. snuck
- Snipe hunt
- Snitch
- So to speak
- Sob sister and sob story
- Social vs sociable
- Sojourn vs adjourn
- Solder vs soldier
- Soldiers, marines, airmen, sailors
- Soliloquy vs monologue
- Solitaire and patience games
- Some odd
- Some way vs. someway
- Somebody vs. someone
- Someday vs. some day
- Someplace vs. some place
- Sometime vs. some time
- Sooner rather than later
- Sophistry
- Sort of
- Sorted vs sordid
- SOS and Mayday
- Sound bite
- Sow wild oats
- Spanish fly
- Spartan
- Spatter vs. splatter
- Speak to
- Spearhead
- Speciality vs. specialty
- Species
- Spectra vs. spectrums
- Sped vs. speeded
- Spendthrift
- Spiel
- Spiffy
- Spilled vs. spilt
- Spin doctor
- Spinster
- Spit and image vs. spitting image
- Spite vs respite
- Spoiled vs. spoilt
- Spoof
- Spore vs spoor
- Spouse vs espouse
- Spreaded
- Spur vs spurn
- Spur vs. spurn
- Squinch
- Stadia vs. stadiums
- Stalactite, stalagmite
- Stanch vs. staunch
- Stand alone vs standalone
- Standby vs. stand by
- Stank, stunk
- Stat vs now
- State of the art
- Stationary vs. stationery
- Statue vs statute
- Status quo
- Statute of limitations
- Stir-crazy
- Stock vs stalk
- Stock, shares
- Stockholm syndrome
- Stocking stuffer and stocking filler
- Stone cold and stone-cold
- Stool pigeon
- Straight from the horse's mouth
- Straight vs. strait
- Stratagem vs. strategy
- Strategy vs tactic
- Striped/striping vs stripped/stripping
- Strived, striven, strove
- Stroller or pushchair
- Strop vs strap
- Stuffing vs dressing
- Stupefaction
- Sub rosa vs sub-rosa
- Sub vs infra
- Subconscious vs. unconscious
- Subject to vs subjected to
- Subjugated vs subjected to
- Subordinating conjunctions
- Suborn
- Subpoena
- Substantial vs. substantive
- Subtext
- Suffice it to say
- Sui generis
- Suit vs suite
- Sulk vs skulk
- Summa cum laude or magna cum laude
- Summons and summonses
- Super vs ultra
- Supercilious
- Supermoon
- Superstorm
- Supposably
- Surely vs surly
- Surgeon vs sturgeon
- Surplus vs surplice
- Surrogacy
- Suspect, person of interest or perpetrator
- Sutler vs settler
- Swan song
- Swanning around and swanning about
- Swatch vs swath
- Swath vs. swathe
- Sweat vs. sweated
- Swing for the fences
- Sword of Damocles
- Symbolic vs symbiotic
- Synonyms
- Systematic vs systematical
- Systematic vs. systemic
T
- Tacit vs taciturn
- Tack vs. tact
- Take a toll and take its toll
- Take the mickey out of someone
- Take the reins
- Takeaway and takeout
- Taken aback
- Talk turkey
- Tamper vs temper
- Tanker vs tankard
- Taper vs tapir
- Tar baby
- Tariff
- Taro vs tarot
- Tartar or tartare
- Tattletale vs telltale
- Taut vs taunt
- Tautology
- Tease out
- Teetotaler, teetotaller
- Telegram vs. telegraph
- Temblor, tremblor or trembler
- Temporal vs Templar
- Tenure vs tenor
- Terminate
- Terrific vs terrifying
- Terroir and terror
- Testament vs. testimony
- Tete-a-tete
- Than vs. then
- Thanksgiving or Thanksgiving Day
- That or who
- That vs. which
- That which
- The $64,000 question
- The Bronx
- The die is cast
- The end justifies the means
- The jaws of life
- The late
- The penny dropped
- The pot calling the kettle black
- The rub
- The vs thee
- Their, them, themselves, they (as singular pronouns)
- Them's the breaks or brakes
- Therefore vs therefor
- Think outside the box
- Third rail
- Tho, altho
- Thong or flip-flop
- Thoroughbred vs purebred
- Thrall
- Throw the baby out with the bathwater
- Throw under the bus
- Thrust, thrusted
- Thumbs up and thumbs down
- Thusly
- Tic vs. tick
- Tiddlywinks and tiddleywinks
- Till, until, 'til
- Titular
- TMI
- To a T
- To boot
- To cry wolf
- To hear crickets
- To the bitter end
- To the nines
- To vs. too
- To wit
- Toe the line
- Toile vs toil
- Toile vs tulle
- Toilette
- Tolerance vs. toleration
- Tomayto, tomahto and potayto, potahto
- Tomfoolery
- Tongue-in-cheek
- Tontine
- Tool vs tulle
- Top banana and second banana
- Topography vs. typography
- Torrent vs torrid
- Torturous vs. tortuous
- Touch and go
- Touch base
- Tough row to hoe
- Tour de force
- Tout
- Toxicology vs. toxology
- Track and field and athletics
- Track vs tract
- Tractable vs trackable
- Tragedy vs travesty
- Training wheels vs stabilisers
- Traitor vs trader
- Transgender, transsexual, transvestite
- Translucent vs. transparent
- Transparent, translucent and opaque
- Transpire
- Transport vs. transportation
- Trap vs entrap
- Trawl vs. troll
- Treatise vs treaties
- Treble vs. triple
- Trepidation
- Triage
- Troglodyte
- Trolling
- Troop vs. troupe
- Truck with
- Truculent
- Trustee vs. trusty
- Tsk-tsk
- Tsunami vs tidal wave
- Turbid, turgid, torpid
- Turducken
- Turpitude vs turpentine
- Turtle, tortoise, terrapin
- Tussie-mussie vs nosegay
- Twee
- Tween or teen
- Two-bit
- Two-time
U
- U.S. state demonyms
- Uber
- Ubiquitous
- Udder vs. utter
- Ulterior motive
- Unawares
- Uncle Sam
- Uncomparable adjectives
- Underlie or underline
- Undoubtably vs. undoubtedly
- Unexceptionable vs unexceptional
- Unfamous or infamous
- Union Jack
- Unique
- United States (plural or singular?)
- Unkempt, unkept
- Unknown quantity
- Unsung hero
- Unwitting vs unwilling
- Up to date
- Up to snuff
- Upfront vs. up front
- Upload vs download
- Upmost vs. utmost
- Upper crust
- Upshot
- Urban vs urbane
- Urban, suburban and rural
- Used to
- Usually always
V
- Vacuous vs. vapid
- Vagina vs. vulva
- Valedictorian and salutatorian
- Vamoose
- Vanguard
- Variance vs variants
- Varied vs various
- Vaudeville
- Vegetarian vs vegan
- Venal vs venial
- Veracity vs. voracity
- Verbatim vs paraphrase
- Verbiage
- Vernacular
- Verses vs. versus
- Vertex vs. vortex
- Vertigo vs vertiginous
- Very
- Vested
- Veteran vs veterinarian
- Vice versa
- Vicissitude
- Vigilant vs vigilante
- Vim and vigor
- Violation vs volition
- Viral vs virile
- Vis-a-vis
- Visor vs vizier
- Vitiate
- Vitriol vs vitreous
- Vittle vs vital
- Viz.
- Vouchsafe
W
- Waddle vs. wattle
- Wainscot or chair rail
- Waive vs. wave
- Waiver vs. waver
- Wake vs awake
- Wallop and pack a wallop
- Wander vs. wonder
- Wane, wax
- Wangle vs wrangle
- Wanton vs. wonton
- Wary vs. weary
- Was vs were
- Washed up or all washed up
- Wassail
- Water under the bridge
- Waterloo or meet one's waterloo
- Watt vs what
- Weakest link
- Weaved, wove, woven
- Website vs. web page
- Weekend
- Well-heeled
- Welsh
- Wench vs winch
- Were vs we're
- Wet vs. whet
- Whatnot
- Whence vs. from whence
- Whereas
- Whig vs wig
- While away vs. wile away
- Whilst
- Whiny, whiney, whinny, Whinney
- Whippersnapper
- Whiskey vs. whisky
- White Christmas
- White lie
- Who vs. whom
- Who's vs. whose
- Who's Who
- Whoever vs. whomever
- Whoop vs. whup
- Widow, widower
- Wiki
- Will-o'-the-wisp
- Win-win or lose-lose
- Wink vs blink
- Wit vs. whit
- Wither vs. whither
- Wobble vs warble
- Wonder vs. wonderment
- Wont
- Wont vs won't
- Woolgathering
- Word to the wise
- Work in progress vs work in process
- Workout vs. work out
- Worse comes to worst
- Worth one's while
- Would have, would've or would of
- Would just as soon or assume
- Wrap one's head around
- Wreak havoc (and wreaked vs. wrought)
- Wreak vs wreck
- Wrench and spanner
- Writ large
- Writer's block
- Wrong vs. wrongly
- Wunderkind
Y
- Y'all
- Yam vs sweet potato
- Yea, yeah, yay
- Yester
- Yiddish
- Yoke vs. yolk
- Youthquake
- Yuletide
Z
- Zee vs. zed
- Zeitgeist
- Zero-sum game
- Zigzag