Boundaries on the SAT: punctuation lesson and practice
Boundaries questions ask which punctuation belongs where two parts of a sentence meet. Two complete sentences need a period, a semicolon, or a comma with and, but or so. An extra phrase opens and closes with the same mark. No single mark goes between a subject and its verb. A colon follows a complete sentence to introduce a list or explanation.
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The rules that cover most questions
| Situation | Correct | Wrong |
|---|---|---|
| Two complete sentences | closed; we · closed. We · closed, so we | closed, we (comma splice) |
| Extra phrase in the middle | Faiz, a poet, wrote | Faiz, a poet wrote |
| Long subject, then verb | The students who finished early helped | …finished early, helped |
| "However" between sentences | hard; however, most | hard, however, most |
| List after a full sentence | three things: flour, sugar | things; flour · such as: flour |
The 5-second test
- Cover everything after the blank. Is the part before it a complete sentence?
- Cover everything before the blank. Is the part after it a complete sentence?
- Both complete? You need a period, semicolon, or comma plus and/but/so.
- Only the first complete, followed by a list or explanation? Use a colon.
- Neither side complete? Usually no punctuation, or a comma that matches one earlier in the sentence.
Example
The ancient city of Mohenjo-daro had a carefully planned drainage ______ brick channels ran beside many of its streets.
Both sides are complete sentences, so the answer is system; covered (or system. Covered). "system, covered" is a comma splice.
Semicolons act like periods
If a period would be correct, a semicolon usually is too. If a period would be wrong, so is a semicolon. Never put a semicolon before a list or a phrase that is not a full sentence.
Common mistakes
Sample questions with answers
1. Truck art is a popular folk tradition in ______ cover vehicles with bright flowers, birds, and lines of poetry.
- Pakistan, artists
- Pakistan; artists (correct)
- Pakistan artists
- Pakistan and, artists
Both sides are complete sentences, so a semicolon is needed. A comma alone is a comma splice.
2. Faiz Ahmed Faiz, one of the most celebrated Urdu ______ often wrote about justice and hope.
- poets
- poets;
- poets, (correct)
- poets—
The extra phrase opens with a comma, so it must close with a comma.
3. The festival menu featured three regional ______ chapli kebab, sajji, and biryani.
- dishes;
- dishes: (correct)
- dishes, such as:
- dishes
A colon introduces a list after a complete sentence. A semicolon needs a complete sentence on both sides.
Frequently asked questions
What are Boundaries questions on the SAT?
They are punctuation questions in the Standard English Conventions part of Reading and Writing, which makes up about 26% of the section, roughly 11 to 15 questions. They test periods, semicolons, commas, dashes and colons.
When do you use a semicolon on the SAT?
Use a semicolon between two complete sentences that are closely related. If a period would work, a semicolon usually works too.
Is a comma before "however" correct?
Only in the middle of one sentence. When "however" joins two complete sentences, it needs a semicolon or period before it and a comma after it.
Can a colon come after "such as"?
No. A colon must follow a complete sentence. "Such as:" and "including:" are treated as errors on the SAT.