Ask two different English teachers how to use commas, and you’ll likely get two different answers. For example, certain teachers and style guides favor the Oxford comma (that handy little comma that distinguishes between having eggs, toast, and orange juice for breakfast or having eggs with orange juice on toast), while others don’t.
The truth is that people don’t always agree on the rules surrounding commas. Thankfully, though, the SAT and ACT are not arbitrary; they’ll only test you on the rules that are objectively correct in academic writing. So, what are those rules?
Here are few concrete comma rules that will help you tackle the tests.
Rule 1: When used with a conjunction, a comma can join two independent clauses.
Explanation: An independent clause could stand on its own as a sentence. So, let’s say you have the following two independent clauses: “I am planning to take the ACT. I hope to improve my English score.” We couldn’t join these two clauses with just a comma (“I am planning to the take the ACT, I hope to improve my English score.”) That’s a common error called a comma splice. As my students from Summer 2017 can attest, I am a stickler for avoiding comma splices—and so are the tests.
You can join these two clauses with a comma, but you need one more piece: a small, handy word called a conjunction. For, and, nor, but, or, yet, and so are common conjunctions.
So, let’s put this together. We could join those two independent clauses with a comma and conjunction as follows:
I am planning to take the ACT, and I hope to improve my English score.
That’s it! Be on the lookout for comma splices on the tests, and remember that if you are trying to join two independent clauses, a comma + a conjunction is an effective method.
Rule 2: Place a comma after an introductory dependent clause.
Explanation: We know now what an independent clause is, so it’s easy to discern what a dependent clause is—something that could not stand on its own. It depends on an independent clause. For example, “While studying is a lot of work, it will really help me succeed.” Here, “It will really help me succeed” is an independent clause. “While studying is a lot of work” couldn’t stand on its own; it depends on the other clause.
Thus, as in this example, make sure you place a comma after an introductory dependent clause.
Rule 3: Use commas to frame nonessential phrases.
Explanation: Think of nonessential phrases as extra information. Basically, the sentence would still work grammatically and convey the same meaning if we took the nonessential phrase out. Let’s say you get two new puppies (!). You might write, “My new dogs, which are both terrier mixes, love to play together.” It’s nice
to know that the two dogs are both terrier mixes, but in this case, it’s just extra information. The sentence would still make just as much sense and would still work grammatically if we took it out, i.e. “My new dogs love to play together.”
On the tests, ensure that nonessential information is framed by the same piece of punctuation. If they give you a comma to open the information, make sure you choose a comma to close it. You can also use dashes to frame nonessential information, which generally just gives more emphasis to the information being provided. Either way, the most important part is that they match.
These are just a few of the comma rules you’ll encounter on the test, but I hope they’ll help you make sense of some of the common types of questions you’ll see. Be sure to review punctuation rules and to complete ACT and SAT practice tests to prepare. Then, incorporate the rules you’ve learned into your own writing. If you know the rules, use them—it can only help your score on the essay too (click here for more tips on writing effective SAT and ACT essays!).