Properly incorporate restrictive elements (e.g., restrictive appositives/clauses). | Form, Structure, and Sense | SAT Reading and Writing

Use commas only around nonrestrictive information.

Core Idea

Restrictive elements are essential to identifying which person, thing, or idea the sentence is about. They never take commas because removing them would change the sentence's meaning.

Understanding

Some parts of a sentence define or restrict which noun you're talking about. These are restrictive elements — and the SAT tests whether you can spot them and punctuate them correctly.

Compare:

The students who passed the exam were invited to the reception. (Only those who passed — the clause restricts which students.)
The students, who passed the exam, were invited to the reception. (All the students passed, and by the way, they were invited.)

The first version uses no commas because the clause is restrictive — it's essential for meaning. Remove it and you don't know which students. The second version uses commas because the clause is nonrestrictive — extra info, nice to know, but not needed to identify the students.

Restrictive appositives work the same way:

The novelist Toni Morrison won the Nobel Prize. (No commas — "Toni Morrison" specifies which novelist.)
My mother, a retired teacher, lives in Ohio. (Commas — "a retired teacher" is extra info, not needed to identify "my mother.")

The SAT test: if you remove the element, does the sentence still clearly identify its subject? If no, the element is restrictive — no commas. If yes, it's nonrestrictive — use commas.

Step by Step

Identify the element (clause, appositive, or phrase) that might be restrictive or nonrestrictive.
Mentally remove it from the sentence.
Ask: does the sentence still clearly identify which specific person, thing, or group it's referring to?
If removing it makes the reference vague or changes the meaning → it's restrictive → no commas.
If the sentence still works fine without it → it's nonrestrictive → use commas.

Misconceptions

Thinking all "who" and "which" clauses need commas. Only nonrestrictive ones do. "The book that I borrowed" and "the student who scored highest" are restrictive — no commas.
Using "which" as a signal for nonrestrictive and "that" for restrictive as an absolute rule. While "that" is always restrictive, "which" can be either — context and commas determine it.
Placing commas around appositives automatically. If the appositive is needed to identify the noun ("the poet Robert Frost"), it's restrictive and takes no commas.

Question

Worked Example

Marine biologist Rachel Carson, __________ is widely credited with advancing the global environmental movement, published her groundbreaking book Silent Spring in 1962.

Select an answer to see the explanation