IELTS grammar: Apostrophes and Possessives

Apostrophes in English do exactly two jobs, and almost every error in this category comes from confusing which job is being done in a given word: they mark possession ("the student's essay" — something belonging to the student) or they mark a contraction, standing in for missing letters ("it's" for "it is," "don't" for "do not"). The reason this small punctuation mark is worth a dedicated review, rather than being dismissed as a minor detail, is that apostrophe errors are unusually visible on the page — a misplaced or missing apostrophe stands out against surrounding text in a way that a subtle tense error often doesn't, and a pattern of apostrophe errors across a script reads as a gap in basic mechanical control even when the sentence-level grammar elsewhere is genuinely strong.

For singular nouns, possession is formed by adding "'s," and this holds even when the noun already ends in "s": "the student's essay" (one student), "the boss's decision," "James's book." Some style guides allow a bare apostrophe with no additional "s" for names ending in "s" that are already pronounced with an extra syllable in the possessive ("James' book" as an alternative to "James's book"), and both are generally accepted, but the "'s" form is the safer, more universally correct default to use consistently rather than trying to judge which specific names qualify for the exception.

For plural nouns that already end in "s," possession is formed by adding only an apostrophe after the existing "s," with no additional "s": "the students' essays" (multiple students, each with an essay, or a shared set of essays belonging to the group), "the workers' rights," "the companies' shared responsibility." For plural nouns that do not end in "s" — a genuinely irregular plural like "children," "people," "men," or "women" — the possessive still adds "'s" exactly as a singular noun would: "the children's toys," "the people's choice," "the men's changing room." The distinguishing test is not whether the noun is plural in meaning, but whether it ends in "s" in its plural written form.

Joint possession versus individual possession is a subtler distinction worth knowing for more complex sentences. When two people jointly possess one shared thing, only the second name takes the possessive marker: "Tom and Jerry's house" (one house, shared by both). When two people separately possess their own, distinct things, both names take the possessive marker individually: "Tom's and Jerry's opinions differed sharply" (two separate opinions, one belonging to each). This distinction rarely appears in everyday Task 2 writing, but it does come up when discussing shared versus individual responsibility, ownership, or policy positions between two named parties or institutions, and getting it backwards can genuinely obscure whether one thing or two things are being described. A GT letter is actually a more natural place for this pattern to appear than an essay, since letters often describe specific named people and their individual or shared circumstances — "my sister and her husband's new apartment" versus "my sister's and her husband's individual work schedules" shows the same shared-versus-separate logic applied to a genuinely personal, informal context rather than an abstract policy one.