Essential and nonessential elements — Digital SAT Reading & Writing practice
Appositives and clauses that add extra versus necessary information.
Key ideas to know
Testing Essential vs Nonessential Info
Remove the underlined phrase from this sentence. Does the core meaning change? The new library, funded by local donations, opened yesterday.
No. The phrase adds extra details and can be removed without changing the core subject-verb meaning (The new library opened yesterday), so it is nonessential and needs commas.
Watch out: Students often add commas to every descriptive phrase instead of testing if the information is required for identification.
Commas with Appositives
Choose the correct punctuation for the appositive: The poet ___ Maya Angelou wrote extensively about racial identity.
No commas. The phrase Maya Angelou is essential because it identifies which poet we are discussing. Essential appositives take no commas.
Watch out: Placing commas around an appositive when the noun already uniquely identifies the person or thing, like The president or My mother.
Choosing Between Which and That Clauses
Select the correct relative pronoun for this sentence: The research paper ___ we submitted yesterday received top marks.
That. The clause we submitted yesterday is essential to identify which paper, so use that with no commas. Use which only for nonessential clauses set off by commas.
Watch out: Using which without commas for essential information or adding commas to that clauses, both of which break standard convention rules.
The Single Comma Interrupter Error
Fix the punctuation error in this sentence: The coach, announced the new training schedule and left the gym immediately.
Remove the comma after coach. A single comma cannot separate a subject from its verb or interrupter. Use either no commas or a matching pair: The coach announced... or The coach, however, announced...
Watch out: Inserting one comma to mark the start of an interrupter but forgetting the closing comma, which incorrectly splits the subject from its verb.
Identifying Essential Clauses
Is the underlined clause essential or nonessential? The students who studied for the exam passed with high scores.
Essential. The clause who studied for the exam is required to identify which students passed. Without it, the sentence claims all students passed, changing the meaning. Essential clauses take no commas.
Watch out: Assuming all descriptive clauses are extra information that can be removed without altering the specific group or item being discussed.