The one-second replacement test
Read the sentence out loud with it is in place of the word. Then read it with the possessive meaning “belonging to it”.
- If
it isfits, the word is it's. - If
it isdoes not fit, the word is its.
| Sentence | Try “it is” | Correct form |
|---|---|---|
| The dog wagged ___ tail. | The dog wagged it is tail. no | its |
| ___ raining outside. | It is raining outside. yes | it's |
| The team lost ___ first match. | The team lost it is first match. no | its |
| ___ been a long week. | It has been a long week. yes | it's |
What each form does
its — possessive
its is the possessive form of it. It answers the question “whose?” and it never takes an apostrophe, just like his and hers never do.
The company changed its logo. The cat licked its paw. The plan has its merits.
it's — contraction
it's is a shortened form of it is or it has. The apostrophe marks the letters that were dropped, exactly as in don't and we're.
It's late. It's been raining. It's a fair question.
Why its breaks the pattern you learned
Most possessives do take an apostrophe: the dog's bone, the student's essay, Maria's idea. That rule applies to nouns. Pronouns follow a different rule. his, hers, ours, theirs and its show possession with no apostrophe at all. The apostrophe in it's belongs to the contraction, so it can never also mark possession.
Memory hook. Possessive pronouns never carry an apostrophe. If you write it's for possession, you have written “it is” by accident.
Three mistakes to look for
- “It's own”. The robot cleaned it's own sensors. Write its own. “It is own” makes no sense, so the test fails immediately.
- “Its raining”. Its raining again. Write It's raining again, because “it is raining” is a complete sentence.
- “Its been”. Its been three years. Write It's been three years, because the full form is “it has been”.
When the sentence has both forms
A sentence can need both words, and each one passes a different test.
It's clear that the city has changed its transport plan.
The first word replaces “it is”. The second answers “whose transport plan?”. Check them one at a time and neither becomes ambiguous.
Check a whole paragraph
The apostrophe checker on this site scans pasted text for its/it's mix-ups, missing possessive apostrophes and who's/whose errors. It names the rule behind each flag and shows a correction.
Open the apostrophe checker