An SAT Reading & Writing micro-topic under Form, Structure and Sense (Expression of Ideas + Standard English Conventions). Free to read — no account needed.
A pronoun stands in for a noun called its antecedent, and the two must agree in number. If the noun is singular, the pronoun must be singular; if the noun is plural, the pronoun must be plural.
A single thing takes a singular pronoun. "Antwerp doubled its population" is correct because "Antwerp" is one city, so the singular "its" matches. "Their" would be wrong here.
Watch for nouns that sound like groups but are grammatically singular, such as a company, a team, or a country — they usually take "it" or "its." A word like "vernacular" or "language" is also singular, so a later pronoun should be "it," not "they."
To check, find the exact noun the pronoun refers to, decide whether it is singular or plural, then match the pronoun. Do not be thrown off by other nouns that happen to sit nearby.
Worked examples
A sentence reads: "The museum extended _____ hours for the summer." Should the blank be "its" or "their"? Use "its." "The museum" is a single institution, so the singular pronoun agrees; "their" would wrongly treat it as plural.
A sentence reads: "The researchers published _____ findings in a journal." Should the blank be "its" or "their"? Use "their." "The researchers" is plural, so the plural pronoun agrees.
A sentence reads: "While the vernacular attracted writers, they tended to overload _____ with Latinisms." Should the blank be "it" or "them"? Use "it." The pronoun refers to "the vernacular," which is singular, even though "writers" appears nearby.
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