The SAT and ACT English sections commonly confuse students into thinking punctuation is required where it’s not. If it doesn’t NEED punctuation, then don’t use it. There are only three cases in which the comma should be used on the test.
1. Removable Clauses
Removable clauses are clauses that can be removed from the sentence without altering the point or the meaning of the sentence.
Jenny, a fan of Gossip Girl, went to the store to buy the series on DVD.
The bolded section should be sectioned off with commas, because it is entirely removable.
2. Introductory Clauses
Introductory clauses introduce a sentence. If they are deleted, what remains is still a complete sentence (subject, verb). The rest of the sentence stands on its own, even if it’s not as clear without the introductory clause.
If you want to be an Olympic athlete, you must train hard every single day.
You must train hard every single day. Still a full sentence.
Lists need commas, as you know! Separate each item in a list with a comma.
It is necessary to train dogs, cats, and horses.
People disagree about whether or not there should be a comma before “and.” You will never be tested on this rule.
There, that’s it! Only use a comma in these three situations. Don’t let an answer choice with extra commas convince you that extra commas are necessary.