If you’ve ever found yourself staring at a punctuation question on the SAT wondering whether to pick a period or a semicolon, here’s the truth: it doesn’t actually matter—at least not grammatically. On the SAT, these two punctuation marks serve exactly the same purpose. Once you realize that, this whole category of questions becomes much easier.
The Big Idea
Both periods (.) and semicolons (;) can separate two complete sentences—meaning each side of the punctuation must be able to stand alone as a full thought. That’s it. That’s the entire rule.
For example:
“Maria worked hard for years; she finally earned her scholarship.”
and
“Maria worked hard for years. She finally earned her scholarship.”
Both sentences are perfectly correct. The semicolon and period are doing the same grammatical job—they’re just punctuating the sentence differently.
The SAT Trick: When They Both Appear
Here’s a classic SAT move: you’ll sometimes see a question where both a period and a semicolon appear among the answer choices. When that happens, you might consider crossing both of them out. Because they mean the same thing, the test likely wouldn’t include both unless neither is correct.
In those cases, look for what’s really being tested—it might be that the sentence actually isn’t two complete sentences, or that another choice (like a comma plus “and”) fits the structure better. Recognizing this pattern can save you valuable time and spare you from overthinking.
The Real Mistake to Watch For
The only major punctuation error the SAT is trying to catch you on here is the comma splice—when someone tries to connect two complete sentences with just a comma.
Incorrect: “Maria worked hard for years, she finally earned her scholarship.”
A comma simply isn’t strong enough to join two independent clauses by itself.
To fix it, you could use:
“Maria worked hard for years. She finally earned her scholarship.”
or
“Maria worked hard for years; she finally earned her scholarship.”
or
“Maria worked hard for years, and she finally earned her scholarship.”
All three are correct because they properly connect or separate two complete ideas.
So, When Should You Use Which?
Grammatically speaking, it doesn’t matter. Stylistically, though, a semicolon can make the connection between two ideas feel a little closer, while a period gives a cleaner, more distinct break. But the SAT isn’t testing style—it’s testing correctness. On the exam, both are equally valid ways to separate two complete sentences.
The Bottom Line
If you can remember just one thing, make it this: on the SAT, a period and a semicolon do the same job. If both appear as answer choices, that’s your clue that neither one is right. The real challenge is figuring out whether you’re dealing with one complete sentence or two—and once you can tell the difference, these questions become some of the easiest points on the test.
A Final Thought
Understanding how punctuation actually works on the SAT is one of those small but powerful confidence boosters. Once you see that the test isn’t trying to trick you with obscure grammar rules, it starts to feel more predictable—and maybe even a little friendlier. Every clear rule you master gives you one less reason to stress and one more reason to trust your instincts on test day.