Pronoun Agreement — Who Matches What?

Every pronoun must clearly refer to a specific noun (its antecedent) and match in number.

Wrong: "Each student must bring their calculator."

Right: "Each student must bring his or her calculator." ("Each" is singular on the SAT)

Ambiguous reference:

Wrong: "When Sarah met Emily, she was nervous." (Who was nervous?)

Right: "When Sarah met Emily, Sarah was nervous."

Common SAT traps:

"Everyone" / "each" / "every" / "anyone" — all SINGULAR

"They" referring to a singular noun — the SAT marks this wrong

Strategy: When you see a pronoun, immediately ask: what noun does this replace? If it's unclear or doesn't match in number, it's wrong.

Reference:

Wikipedia: Pronoun

https://en.wikipedia.org/wiki/Pronoun