how ever (however)

Use its for possession (belonging to something). Use it's only as a contraction for "it is" or "it has." A quick substitution test and a few handy rewrites fix most errors.

Below: a one-line rule, easy memory tricks, many real-world wrong/right pairs, context-specific examples for work, school, and casual writing, and copy-paste rewrites you can use immediately.

Quick answer

Its = possessive. It's = contraction for it is or it has.

Possessive: its tail, its owner, its price.
Contraction: It's raining (It is raining), It's been a long day (It has been a long day).
Test: replace with "it is" or "it has." If the sentence still makes sense, use it's; otherwise use its.

Core grammar: the simple rule

its is a possessive pronoun (like his, her, our). It never takes an apostrophe. it's is a contraction for it + is or it + has; the apostrophe marks missing letters.

Apply the substitution test: expand to "it is" or "it has." If expansion fits, keep the apostrophe; if it breaks the sentence, use its.

Possessive: The company updated its policy. ("the company updated it is policy" makes no sense)
Contraction: It's unlikely we'll finish today. (expands to "It is unlikely...")
Wrong: The dog wagged it's tail. -
Right: The dog wagged its tail.

Memory trick: fast checks that stick

Three quick checks you can do without thinking:

Expansion test: try "it is" or "it has." If one fits, use it's.
Possession check: if the word shows ownership (like his or hers), use its (no apostrophe).
Pronoun rule: possessive pronouns never take apostrophes.

Cheat-sheet: 60-second editing test

Replace → Read → Rewrite. If the test is unclear, rewrite to remove ambiguity.

Replace the word with "it is" or "it has."
Read the sentence aloud to check flow and meaning.
If still ambiguous, rewrite: use "the X's Y" or "the Y of the X" instead of the risky form.

Example: Original: "It's number wasn't listed." Test: "It is number wasn't listed" fails →
Correct: "Its number wasn't listed."

Common wrong/right pairs - fast practice

Scan the wrong sentence, apply the expansion test, then read the corrected version.

Wrong: The company posted it's annual report on Tuesday. -
Right: The company posted its annual report on Tuesday.
Wrong: It's collar was red after the groomer left. -
Right: Its collar was red after the groomer left.
Wrong: The tree lost it's leaves much earlier than usual. -
Right: The tree lost its leaves much earlier than usual.
Wrong: The robot completed it's task ahead of schedule. -
Right: The robot completed its task ahead of schedule.
Wrong: The book had it's own chapter on design patterns. -
Right: The book had its own chapter on design patterns.
Wrong: Everyone loves the restaurant for it's atmosphere. -
Right: Everyone loves the restaurant for its atmosphere.

Try your own sentence

Test the whole sentence, not just the phrase. Context usually makes the right answer obvious.

Real usage: work, school, and casual examples

Three quick examples per context, with a short note explaining why each is correct.

Work: Please upload the dataset and confirm its location in the shared folder. (its = possession)
Work: It's critical that we finish the audit by Friday. (it's = it is)
Work: The server reported its status as "degraded" during the outage. (its = possession)
School: The cell maintained its shape after staining. (its = possession)
School: It's important to include a control group in the experiment. (it's = it is; expand in formal writing if preferred)
School: The essay lost some precision when the author changed its thesis midway. (its = possession)
Casual: I can't find my keys; it's probably under the couch. (it's = it is)
Casual: My bike lost its bell again - I'll fix it tonight. (its = possession)
Casual: The cat cleaned its whiskers and then curled up - it's adorable. (first = possession, second = it is)

Rewrite help: hands-on fixes and examples

If the substitution test leaves you unsure or the phrasing feels awkward, rewrite. Here are multiple fixes for common mistakes so you can pick the tone you want.

Original: "It's tail tapped the glass." → Fixes: "Its tail tapped the glass." / "The dog's tail tapped the glass."
Original: "I think it's broken its mechanism." → Fixes: "I think it has broken its mechanism." / "I think its mechanism is broken."
Original: "It's owner called this morning." → Fixes: "Its owner called this morning." / "The owner called this morning."
Original: "It's price increased dramatically." → Fixes: "Its price increased dramatically." / "The product's price increased dramatically."
Original: "It's update fixed the bug." → Fixes: "Its update fixed the bug." / "The update fixed the bug."
Original: "Its not ready yet." (typo) → Fixes: "It's not ready yet." / "It is not ready yet."

Punctuation, hyphenation and spacing: apostrophes matter

Apostrophes mark contractions or noun possession (the dog's bone) but not possessive pronouns (its). Don't add spaces around apostrophes. Hyphens don't change the its/it's rule; if punctuation confuses readers, rewrite for clarity.

Correct: it's, its.
Incorrect: it 's or its'. (Unless forming a possessive plural like owners'.)
Do not use an apostrophe to form most plurals (CDs, not CD's).
Avoid using hyphens to force meaning; instead rewrite: "its-like behavior" is acceptable when clear, but consider rephrasing.

Usage: Wrong spacing: "it 's" → Correct: "it's".
Usage: Wrong: "The team changed it's-structure." →
Correct: "The team changed its structure."
Usage: Wrong plural: "CD's" → Correct: "CDs".

Similar mistakes to watch for

Writers who mix up its/it's often slip on other apostrophe or homophone pairs. Use the same substitution and read-aloud checks.

your vs you're: your = possession, you're = you are.
their vs there vs they're: their = possession, there = place, they're = they are.
whose vs who's: whose = possession, who's = who is / who has.

Usage: Wrong: "Your going to love this." →
Right: "You're going to love this."
Usage: Wrong: "There dog chewed the shoe." →
Right: "Their dog chewed the shoe."
Usage: Wrong: "Whose coming to dinner?" →
Right: "Who's coming to dinner?"

FAQ

How do I remember whether to use its or it's?

Try the expansion test: replace with "it is" or "it has." If that makes sense, write it's. If not, use its. Also remember possessive pronouns (his, hers, ours, its) never take an apostrophe.

Is "it's" ever a possessive?

No. It's only stands for "it is" or "it has." The possessive pronoun is its without an apostrophe.

Can I rewrite to avoid the issue in formal writing?

Yes. Prefer rewrites in formal texts: write "It is likely" instead of "It's likely," or change possession to "the device's battery" or "the battery of the device."

What if a sentence is ambiguous after the substitution test?

If substitution yields two plausible readings, rewrite for clarity. For example, instead of "Its case was closed" (ambiguous), write "The case was closed" or "The case of it was closed," depending on meaning.

How can I stop making this mistake habitually?

Build a short proofreading habit: when you type its/it's, pause and run the 60-second test (Replace → Read → Rewrite). Use a grammar checker for drafts and keep a few correct templates ready to paste.

Quick check before you send

If unsure, run the expansion test or paste the sentence into a checker. Keep a short list of correct templates from this page and use the rewrites when clarity matters.