SAT® · Reading and Writing: Form, Structure, and Sense — Modifiers, Genitives, and Plurals
Its versus It's
Its shows ownership and never takes an apostrophe. It's is only short for "it is" (or "it has"). Expand the sentence to "it is" to test which one you need.
Most possessives get an apostrophe: the bird's wing, the mason's tools. Its breaks that pattern on purpose. It belongs to a small set of possessive pronouns, alongside his, hers, and theirs, none of which take an apostrophe. An apostrophe in English usually signals either possession on a noun or a missing letter in a contraction. Since its is a pronoun, not a noun, it follows the pronoun rule and stays bare. It's apostrophe is always doing contraction duty, standing in for it is or it has.
The fix takes one second: expand the word to 'it is' and read the sentence back. If the sentence still makes sense, you want it's. If it sounds wrong, you want its, the possessive. A heron that 'defends it is nest' makes no sense, so the sentence needs its nest. But a colony that 'it is the one site on the coast' reads fine, so it's is correct there. This test works every time because it turns a spelling choice into a grammar check you can actually hear.
The same split shows up in whose and who's, which divide along the identical line. Whose is the possessive, used for ownership: the mason whose work won the award. Who's is the contraction of who is or who has: the mason who's working on the tower. Spotting one pair trains you to spot the other, since both rest on the same rule: contractions get apostrophes, possessive pronouns don't.
Key terms
- possessive pronoun
- A pronoun showing ownership, such as its, his, hers, or theirs, that never takes an apostrophe.
- contraction
- A shortened form of two words, like it's for it is, marked by an apostrophe where letters are dropped.
- whose
- The possessive form used to show ownership, as in the mason whose work won the award.
- who's
- The contraction of who is or who has, as in who's working on the tower.
Watch it explained
- How it worksHow does expanding the contraction into 'it is' settle the choice in under a second?
- Worked exampleWalk me through choosing between 'its' and 'it's' twice in a sentence about a bird defending a nest.
- Common mistakeWhy isn't 'it's' the possessive, when every ordinary noun takes an apostrophe to show ownership?
- Going furtherWhat happens with 'whose' and 'who's', which split apart for exactly the same reason?
Check yourself
End of topic.