One of the most significant issues I face with teaching proper grammar is comma usage. Either my students use a comma too much or don’t use it at all. It can be challenging to convince them that it is a useful tool to help clarify their writing.
Luckily, once they see its proper use in writing, they begin to understand how they can use it to ensure their written material is clear and concise to their chosen audience.
Let’s take a look at some basic comma rules to help you determine their proper use so they don’t begin glaring at you from the pages of your text.
How Many Commas Can Be in a Sentence?
There are definite rules of comma use that you must follow, and most sentences will only have one or two commas in them. The overuse of commas can create clumsy sentence structure and confusion, making your sentences difficult to read. This is why understanding comma rules is important.
Basic Comma Usage Rules
The comma is the most used punctuation mark in the English language. But this also means it is one of the most misused as well.
Commas indicate to the reader when to take a short pause and work to connect basic elements within a sentence. It is used to offset details and can help create compound-complex sentences. Without its use, many sentences would just be a jumble of confusing words.
Comma and Compound Sentences
Rarely will you use more than one comma when combining two independent clauses together with a coordinating conjunction. The comma is placed before the conjunction to help form a compound sentence and separate the two complete sentences.
- We drove all day, and when we arrived home the next day, we had to dig our front porch out from under the snow.
Comma in Lists
Sentences that include lists of items will often have three or more commas. This is one of the only times you will see more than two commas in one sentence. Commas can separate items, phrases, and clauses.
- Would you please run to the store and pick up bread, milk, eggs, and cheese for the breakfast casserole?
- Tomorrow I need to write all my lesson plans, grade last week’s papers, and prepare for the holiday vacation.
If a phrase or clause includes a comma, you will separate them using a semicolon instead of a comma. These sentences often include more than one comma as well.
- Our drive home included a stop in Orlando, Florida, where we visited family; Baton Rouge, Louisiana, for a dinner break; and Fort Worth, Texas, to visit the Stockyards.
Comma and Coordinate Adjectives
Adjectives of equal rank (meaning you can switch their order without making their use grammatically incorrect) are separated by a comma. You can use this comma usage in a sentence that contains other comma usage rules, such as independent sentence separation, but creating sentences that are too long can make readability confusing.
- I provided detailed, precise instructions for my house-sitter.
- I provided detailed, precise instructions for my house-sitter, and I left an extra house key in the garage for her as well.
Comma and Introductions
Introductory words, phrases, and clauses are dependent upon the independent clause and require a comma after their use. This provides the reader the knowledge that this initial information is at a close, and the rest of the sentence will follow.
Usually, only one comma is found following a word or dependent clause serving as an introduction to the rest of the sentence. However, they can be combined with other comma rules as long as the sentence doesn’t become too long or rambling.
- Sarah, I need you to run to the store and bring home milk, butter, and bread.
- In the darkness of space, the satellite continued to send back images of all it was pointed towards.
Comma and Parenthetical and Nonessential Expressions
Parenthetical expressions and nonessential expressions are words or phrases that interrupt a sentence. A pair of commas are used to offset this information from the rest of the sentence. There are usually only two commas in these sentences.
- Please be patient, Wyatt, so we can hear all the instructions before we leave.
- Their train collection, in my opinion, is one of the best preserved in the museum.
Nonessential expressions add detail but are not needed for the overall understanding of the sentence.
- My honors students, all ten of them, scored in the top ninety percent of their entire class.
- The rainy weather, which spanned across the entire state, created miserable hiking conditions.
Comma and Other Uses
You’ll see comma use in other rules pertaining to the separation of geological locations, dates, and even addresses. These uses are generally what will add to the overall comma count of a sentence.
- You need to attend the workshops on Monday, December 14; Tuesday, January 23; and Tuesday, February 12, to be eligible for the stipend.
- Sarah Blackmon used to live at 710 S. Boardman St., Racine, Wisconsin, but now she lives at 923 Smith in Green Bay, Wisconsin.
How Many Commas Are Too Many?
This is a common comma question. When your commas exceed basic comma rules or are used incorrectly, then you have used too many. Although some people may argue their comma use is a personal writing style, if comma placement creates confusion, then it probably doesn’t belong.
There is one occasion (which is controversial) that may allow the overuse of commas in a sentence. This is when your text is meant to be read aloud and not as part of the published print.
On this occasion, you are writing for speech, and a comma indicates a pause. When you want to create a pause or slow down your speech rate, adding a comma can create the visual you need to make this occur.
If you feel your sentences have an excess of commas, you need to review the rules of comma use and see if you are placing them correctly. Even if they are used as they should be, you can also choose to turn one longer sentence into two to help break it up.
When writing for speech, you can consider adding an extra comma or two to provide a pause and indicate a slowdown but be sure they are placed where the use will be recognized and not cause confusion.