What this skill covers
This skill is almost entirely mechanical: does the sentence use a comma, semicolon, colon, or period correctly to join or separate its parts, and does the verb agree with its true subject (not just the nearest noun)?
The fastest way to check a boundary question is to test whether the text on each side of the punctuation mark could stand alone as a complete sentence — if both sides can, a comma alone is wrong (comma splice) but a semicolon or period works.
Worked examples
Example 1
Which choice completes the sentence so that it conforms to Standard English? "The lab reviewed the samples _____ each one required a different test."
A. ; each
B. , each
C. each
D. — each, and
Why: Both sides of the punctuation are complete sentences on their own, so a semicolon correctly joins them without creating a comma splice or run-on.
Example 2
Which choice completes the sentence correctly? "The list of approved vendors _____ updated every quarter."
A. are
B. is
C. were
D. have been
Why: The grammatical subject is "list," which is singular, even though "vendors" (plural) sits right before the verb — "is" is the only choice that agrees with the true subject.
How to practice this on TSI Practice Prep
Open SAT Practice to answer original SAT questions on sAT Standard English Conventions, get an explanation for every choice, and see this skill tracked separately in your progress and mistake review.
Practice score estimates are learning indicators, not official scores or admission guarantees.
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