The two main types of conjunctions are coordinating conjunctions and subordinating conjunctions. There are also correlative conjunctions, copulative conjunctions, adversative conjunctions, disjunctive conjunctions, and final conjunctions.
A coordinating conjunction is a conjunction that links two words, phrases, clauses, or sentences that are grammatically equivalent. The six words most commonly used as coordinating conjunctions can be remembered with the mnemonic device FANBOYS—for, and, nor, but, or, yet, so.
Let’s look at a few examples:
We have a porcupine and a kangaroo. [And links two listed elements that are grammatically equivalent.]
You see yet do not hear. [Yet links two grammatically equivalent actions (see and do not hear) performed by you.]
We bathed the dog, but we couldn’t get him clean. [But links two independent clauses.]
Coordinating correlative conjunctions
Some correlative conjunctions (see below for full definition) can function as joint coordinating conjunctions. For example, neither and nor in this sentence introduce grammatically equal elements, so they work together as coordinating conjunctions:
Neither Joe nor John has any idea what he’s talking about.
Coordinating conjunctions and commas
For coordinating conjunctions, comma use depends on the nature of the linked elements. If a coordinating conjunction joins two independent clauses, it usually should be preceded by a comma (e.g., We bathed the dog, but we couldn’t get him clean). If a coordinating conjunction links two listed elements, it doesn’t need a comma (e.g., We have a porcupine and a kangaroo).
The city recommends everyone stay inside because the winds could be dangerous.
In this sentence, because links a dependent clause (because the winds could be dangerous) to the main clause (The city recommends everyone stay inside). We know this is subordinating because because the winds could be dangerous could not normally stand alone as a sentence.
Here are some of the most common subordinating conjunctions:
Some phrases also function as subordinating conjunctions. Here are some of the most common ones:
as far as
as long as
as well as
in order to
in order that
Adversative conjunctions (sometimes known as contrasting conjunctions) are coordinating conjunctions used to express comparisons or contrasts. The element introduced by the adversative conjunction usually qualifies or expresses a caveat with regard to the main clause of the sentence. The most common adversative clauses are but and yet, but still, however, albeit, although, and others are also sometimes adversative.
Let’s look at a few examples of adversative conjunctions:
He’s a shy but loving little boy. [Naples News]
It is a living part of my spiritual life, yet I don’t know if one would call me a religious artist. [Houston Chronicle]
In this sentence, the independent clause introduced by yet adds information to qualify what was expressed in the main clause.
This technology, although not a foolproof way to monitor abusers, might give victims advance warning that danger is approaching. [Hartford Courant]
And in this sentence, the conjunction although introduces information in contrast to the main clause.
Correlative conjunctions are two or more conjunctions used to link structurally identical parts of a sentence. Here are the most common pairs of correlative conjunctions:
|neither–nor||not only–but also|
Elements linked by correlative conjunctions must have parallel grammatical construction. For example, this is technically incorrect (the conjunctions are underlined):
You’re either going to love his work or hate it. [Thousand Oaks Acorn]
For such a construction to be correct, what follows either and what follows or must be syntactically equivalent. A diagram of this example sentence would look like,
The segment following either has an element (the auxiliary verb phrase going to) that the segment following or doesn’t have, so the two segments are not parallel. There are two possibilities for correcting this sentence:
You’re going to either love his work or hate it.
Either you’re going to love his work, or you’re going to hate it.
With sentences this short, correlative conjunctions are usually easy to use correctly. But using more complicated constructions involving correlatives such as not only–but also and if –then can be tricker.
Here’s another technically flawed use of correlative conjunctions:
TTL Inc. is a socially responsible company that is not only known for innovations in engineering but also for its widespread support of education. [UA News]
Here, the verb known should precede not only, as the phrase following but also has no parallel verb.
From the same article, here’s an example of correct correlative conjunction use:
TTL’s passion for advanced education is seen not only in the hours dedicated to volunteering and guest lecturing, but also through endowed scholarships for prospective engineers at The University of Alabama.
Commas and correlative conjunctions
It was either really stupid or really brave.
Our diversity is not only a challenge but also a gift.
b. Use a comma when the two parallel phrases are in separate clauses—for example:
If there’s a truly monumental disaster, then appoint the two last presidents to lend a hand. [WSJ]
c. But even when two correlative conjunctions are in the same clause, it’s often acceptable to insert a comma before the second conjunction either to create a natural-sounding pause, or to prevent confusion.
Copulative conjunctions (also known as additive conjunctions) are coordinating conjunctions used to denote addition. The conjunction indicates that the second word, phrase, clause, or sentence contains an additional fact that is related to the earlier word, phrase, clause, or sentence. Some of the most common copulative conjunctions are and, also, as well as, moreover, no less, and plus.
Some copulative conjunctions may be used to start sentences—for example:
My kangaroo can sing. And she’s not too bad. Moreover, she won a Grammy last year. Plus, she’s a pretty good dancer.
In the last two sentences, moreover and plus come close to becoming adverbs modifying the main verbs of their sentences (won and the contracted is). Such adverbial copulative conjunctions should be set off by commas. And does not need to be set apart.
And is the only copulative conjunction that can be used to introduce a second independent clause within a sentence—for example:
We ate lunch, and we took a nap.
Using any other copulative conjunction in place of and would turn this into a run-on sentence.
Disjunctive conjunctions are conjunctions used to separate two or more mutually exclusive options presented in a sentence. When a disjunctive conjunction is used, it usually indicates either that only one of the elements joined by the conjunctions is true, or that none of the elements are true. The conjunctions most commonly used disjunctively are but, either, else, neither, nor, or, other, and otherwise.
Some disjunctive conjunctions are coordinating conjunctions—for example, the either and the or in this sentence:
Poetry is usually either cheap or free.
Here, either and or indicate that poetry is usually one or the other (cheap or free) but not both. Disjunctive pronouns separate these options.
Other disjunctive conjunctions don’t need to be coordinated. For example, the or in this sentence functions on its own:
I might use papier-mà¢ché, or I might use some kind of wood.
The or separates two options, only one of which can be true.
And in this sentence, the neither and the nor are used to indicate that neither option is true:
Neither he nor his lawyer could be reached for comment.
Final conjunctions (also known as illative conjunctions) are coordinating conjunctions used to introduce clauses or phrases that draw inferences or conclusions from earlier ones. Some of the most common final conjunctions (some of which are phrases) are as a consequence, consequently, for, hence, so, so that, so then, thus, and therefore.
Some final conjunctions introduce phrases within sentences. For example, this sentence has two:
In turn, this causes other asset prices to fall in those nations, thus worsening their banking systems, and hence leading to credit contraction and capital flight. [NY Times]
The phrase introduced by hence draws an inference from the phrase introduced by thus, which in turn draws an inference from the main clause.
Some final conjunctions introduce clauses within sentences—for example:
Equalize the tax laws so that employer-provided health insurance and individually owned health insurance have the same tax benefits. [Wall Street Journal]
Here, the clause introduced by so that infers what will occur should the action proposed in the imperative-mood main clause come to pass.
A final conjunction may also be used to start a sentence that draws a conclusion from the preceding sentence—for example:
Good writing is always about clarity and insight, precision and accuracy. Therefore, this confusing name calls into question the very quality of the writing instruction that will be given in the new department. [Inside Higher Ed]
The second sentence, introduced by the final conjunction therefore, draws a conclusion from the first sentence.
And here’s one more example:
Our current system provides individuals with little market power in the purchase of health insurance. As a result, they typically pay exorbitant premiums. [The New Republic]
Here, the sentence beginning with as a result shows what the conditions described in the first sentence lead to.