Comma Chameleon: When and How to Use Commas
After discussing comma placement in my article, “How to Punctuate Dialogue,” it occurred to me that we all might have an easier time understanding where to put the comma in dialogue if we understood the basics about where commas go in the first place. Despite what seems to be popular belief, they don’t just go wherever you feel like. Unless you’re African American novelist, Jamaica Kincaid, then yes, commas, parentheses, and periods all go wherever you feel like. However, stylistic liberties aside, the following rules should help you understand just where to place that droopy-looking period.
1. Commas separate elements in a series. When listing three or more items, you should separate each item with a comma. You will almost always place a comma before the second to last item (the one that goes before “and” or “or”). The only time you shouldn’t place the comma after the second to last item is when the last two things go together, which is something upon which you should use your best judgment. HINT: You will generally have one less comma than the amount of items in your list (so if you are listing 5 items, you should have 4 commas). Example:
- I went to the store to buy milk, eggs, cheese, bread, and apples.
- I packed shirts, pants, underwear, shoes and socks. (Shoes and socks are things that generally go together, so it would be acceptable to omit the comma after shoes if you wanted).
2. Commas come before FANBOY conjunctions that connect two complete thoughts. FANBOYs are the elementary school acronym for “coordinating conjunctions,” which include the words: for, and, nor, but, or, yet. The key here is that you must have two complete thoughts (aka two “independent clauses). If you cannot separate the part of the sentence that comes before your FANBOY and the part that comes after with a period, then you don’t use a comma. Examples:
- I went to the class, but no one was there. (both “I went to the class” and “no one was there” are complete thoughts)
- I went to the class but didn’t stay long ( no comma here because “didn’t stay long” is not a complete thought as it has no subject).
3. Commas come after interjections. An interjection is a word that expresses an emotion (wow, oh, gee, et al.). Example:
- Oh, I thought you were kidding.
- Gee, your hair smells terrific.
4. Commas come before and after parenthetical clauses and appositives. Parenthetical clauses are those little “side comments” that could be left out except you want to add some juicy detail mid-sentence. Often these little phrases could go in parentheses, but it’s more attractive to put them between commas. Appositives, on the other hand, are phrases that define or describe the preceding word. Examples:
- I was happy, but not too happy, to see him return. (“but not too happy” is the parenthetical clause)
- Josh, my ex-boyfriend, simply was not the one for me. (“my ex-boyfriend” is the appositive)
- The red coat, which I bought last year, is in the closet. (almost always use commas before “which” when used for appositives; however, you wouldn’t want to use commas if you replaced the word “which” with “that.” Use “which” when the appositive is unnecessary to the meaning of the sentence and “that,” with no commas, when you the phrase is needed so the sentence means what you want.)
5. Commas separate cities, states, and countries. No surprise here; you already do this when you write your address. Example:
- I live in Las Vegas, Nevada, USA.
6. Commas separate absolute words/phrases. Absolute words usually occur when you’re talking directly to someone and you want to insert their name or when you answer a question with yes/no. An absolute phrase is a group of words that modifies an independent clause. Examples:
- Yes, I will do that for you.
- Maria, can you call me later?
- Their secret yearnings now revealed, the girls began to blush. ("Their secret yearnings revealed" is an absolute phrase)
7. Commas come after introductory elements. This one is often optional as long as omission of the comma would not result in confusion or change the meaning of the sentence. Example:
- Walking down the street, I noticed it was a beautiful day.
- Surely, you can’t be serious.
8. Commas separate adjacent adjectives and adverbs. When you use more than one adjective and/or adverb with no other word separating them, you must use commas between each. Do not use a comma if the adverb is modifying the adjective. Examples:
- Her pink, rosy cheeks were all aglow. (pink and rosy are two adjectives)
- The very tiring homework assignment is a dull, boring, pointless task. (do not separate very and tiring because very, although an adverb, is modifying tiring not homework)
9. Use commas with dialogue as is explained more in-depth here, in this article. Examples:
- Anita said, “I just love it there!”
- “I’m not going,” Mark announced, “but I hope you’ll enjoy it.”
10. Commas separate subordinating clauses. A subordinating clause (aka “dependent clause”) is a clause that has a subject and a verb yet cannot stand alone (often found having subordinating conjunctions like although, before, whenever, etc). The comma is used to separate the subordinating clause from the main clause (aka “independent clause”), which is a clause that can stand alone as a sentence. Only use the comma if the subordinating clause comes BEFORE the main clause unless the two clauses oppose one another, then you always use a comma regardless of what comes first. Examples:
- If you build it, they will come. (The subordinating clause is “if you build it,” which cannot stand alone as a sentence, and it is followed by a comma because it comes before the main clause. Generally, if/then statements are almost always separated by a comma.)
- They will come if you build it (NO comma here because the subordinating clause comes AFTER the independent clause).
- It doesn’t taste so great, although it looks delicious. (Even though the subordinating clause comes second, it is opposing the main clause, so it must take a comma)
- When it rains, it pours.
11. Use commas after conjunctive adverbs. Conjunctive adverbs connect two independent clauses. This is also when you get to use a semicolon!! Yay! The comma comes after the word, or conjunctive adverb, that connects the two independent clauses. Examples:
- I ate all of my meal; however, I was still hungry. (“However” is the conjunctive adverb)
- It’s a good day for a walk; therefore, that is what I shall do.
12. Use commas in dates. You know this one. Example:
- The date is Friday, September 17, 2010.