Its vs It's: which is correct?

The rule that feels backwards but is simple

Here is the whole rule: it's with an apostrophe is a contraction, and it always expands to either it is or it has. Its with no apostrophe is the possessive form, meaning belonging to it. That is the entire distinction, and the reason it feels counterintuitive is that for almost every other word, an apostrophe plus s signals possession: the dog's bowl, Sarah's car, the company's policy. With it, that pattern is reversed, and the apostrophe means a missing letter, not ownership.

The test is foolproof. Wherever you have written its or it's, try reading the sentence with it is in that spot, and then with it has. If either expansion makes sense, you want the apostrophe version, it's. If neither expansion works, you want the possessive its with no apostrophe. It's a long way home expands to it is a long way home, so it takes the apostrophe. The cat licked its paw cannot become the cat licked it is paw, so it stays possessive.

Why the apostrophe goes the 'wrong' way

The reason its has no apostrophe in the possessive is that it belongs to a small family of possessive pronouns that never use one: his, hers, ours, yours, theirs, whose, and its. None of these takes an apostrophe, because they are already possessive by their very form. You would never write her's or their's, and its follows the same logic. The apostrophe is reserved for the contraction.

English settled into this convention to avoid ambiguity. If its possessive also took an apostrophe, the written language could not distinguish belonging to it from it is at a glance. By giving the apostrophe exclusively to the contraction, the spelling keeps the two meanings visibly separate, even though it means breaking the usual apostrophe-for-possession habit. Once you remember that the possessive pronouns are an apostrophe-free club, its stops feeling like an exception and starts feeling like a member.

Examples to anchor each form

The contraction it's, meaning it is: it's raining, it's a great film, it's too late now, I wonder if it's true. The contraction it's, meaning it has: it's been a long week, it's gone quiet, it's started to snow. In every one of these, you can swap in the full two-word phrase and the sentence still works, which is the signal for the apostrophe.

The possessive its, meaning belonging to it: the phone lost its charge, the plan has its merits, the tree shed its leaves, every dog has its day. None of these can take it is or it has in place of its, which is exactly why the apostrophe stays away. Notice how natural the possessive feels once you stop expecting an apostrophe there; it behaves just like his in the dog wagged his tail.

A sentence that uses both makes the contrast sharp: it's clear the company values its customers. The first is it is (contraction, apostrophe), the second is belonging to the company (possessive, no apostrophe). Reading that line and seeing why each form is what it is will do more than any rule to fix the distinction in your mind.

Catching it in your own writing

This is one of the few errors that a careful proofreading pass reliably catches, because the expansion test is so quick. When you edit, treat every it's and its as a flag and silently expand it: say it is or it has in your head. If the sentence survives, the apostrophe is right; if it collapses into nonsense, delete the apostrophe. The pass takes seconds per instance and never gives a false result.

Autocorrect and spell-check are unreliable here because both spellings are valid words, so the software cannot know which you meant from spelling alone. Grammar checkers that read context do better and will often flag the mistake, but the expansion test in your own head is faster and you should not outsource it. Run the quiz above a few times until the two forms feel automatically different, and the apostrophe will start landing in the right place without conscious effort.