16Hit1600
Standard English ConventionsHardPunctuation: unnecessary comma before restrictive clause

Standard English Conventions practice question

Which choice completes the text so that it conforms to the conventions of Standard English? Students ____ complete the optional lab will earn extra credit toward the final grade.

  1. A. whoCorrect
  2. B. who,
  3. C. , who
  4. D. , who,

Answer: A. who

The clause 'who complete the optional lab' is restrictive—it identifies which students earn credit—so it takes no commas. Any comma (B, C, D) wrongly treats essential information as nonrestrictive and severs the pronoun from its clause or antecedent.

Why the other answers are wrong

B. who,
Placing a comma after 'who' cuts the relative pronoun off from its own clause; besides, this clause is essential to identifying which students earn credit, so it takes no commas at all.
C. , who
A comma before 'who' would mark the clause as nonessential extra information, but 'who complete the optional lab' is exactly what tells us which students earn the credit, so no comma belongs there.
D. , who,
Commas on both sides set the clause off as nonessential, but it's restrictive — it identifies which students — and the second comma also separates 'who' from its verb.

More Standard English Conventions questions

Not affiliated with the College Board. SAT is a trademark of the College Board.