05 — Plurals, apostrophes & possessives (its vs it's)

What this fixes for you: you’ll stop writing “API’s” for plain plurals, you’ll get “the server’s logs” vs “the developers’ commits” right, and you’ll never again mix up its and it’s in a commit message or PR.

The rule in 30 seconds

• Plain plural = just add -s (or -es). More than one thing. No apostrophe ever: APIs, PRs, repos, bugs, IDs.
• Possessive = apostrophe + s. Something belongs to someone: the server's logs, the team's decision, Pravin's branch.
• Plural + possessive = -s first, then just an apostrophe: the developers' commits (commits of many developers).
• it's = “it is” / “it has”. its (no apostrophe) = belongs to it. If you can’t expand it to “it is”, use its.

Why this trips you up

You write commits, PRs, and Slack messages fast, so apostrophes get sprinkled on autopilot — “API’s are down” feels natural but is wrong. As a non-native speaker you also sometimes drop the plural -s entirely (“so much mistake” instead of “so many mistakes”), which hides the difference between one and many. And its vs it's is a coin-flip right now because both sound identical out loud.

See it / fix it

❌ What you tend to write	✅ Correct	Why
merged 3 PR's today	merged 3 PRs today	Plain plural of an acronym — no apostrophe.
the API's return JSON (meaning many APIs)	the APIs return JSON	”More than one API” is a plural, not a possessive.
its failing in prod	it's failing in prod	”It is failing” → use it’s.
the service lost it's connection	the service lost its connection	The connection belongs to it → its (no apostrophe).
the developers commits are messy	the developers' commits are messy	Commits of many developers → plural possessive, apostrophe after the -s.
i fixed so much bug in this PR	I fixed so many bugs in this PR	Bugs are countable → many + plural -s; also capital I.
the server logs is too noisy	the server's logs are too noisy	Logs belong to the server → server's; logs is plural → are.
closed all the ticket's for this sprint	closed all the tickets for this sprint	Plain plural — drop the apostrophe.
the team decision was to revert	the team's decision was to revert	The decision belongs to the team → possessive.
we deployed in the 2020's	we deployed in the 2020s	Plural of a number/decade — no apostrophe.

Patterns to remember

The apostrophe test (run this every time):

1. Am I just talking about more than one? → no apostrophe. repos, PRs, IDs, URLs.
2. Does something belong to one thing? → 's. the bug's root cause, Redis's config.
3. Does it belong to many things already ending in -s? → just '. the users' sessions, the developers' commits.

Plurals cheat sheet:

Word ends in…	Add	Example
most words	-s	bug → bugs, repo → repos
s, x, z, ch, sh	-es	branch → branches, patch → patches, class → classes
consonant + y	-ies	query → queries, dependency → dependencies
acronym / number	-s only	API → APIs, ID → IDs, the 90s

Common irregulars (no -s rule):

Singular	Plural
index	indexes / indices
matrix	matrices
schema	schemas (sometimes schemata)
datum	data (treat “data” as plural or as a mass noun)
person	people
child	children

its vs it’s — the only mnemonic you need:

it's always unzips into “it is” or “it has”. If it won’t unzip, it’s its. “It’s broken” → “It is broken” ✅. “Its README” → “It is README”? ❌ → so use its.

(Same trick works for you're/your and they're/their — the apostrophe version always expands.)

In your daily writing

• Commit messages: Fix the API's rate limiter only if you mean one API’s limiter. For many: Fix the APIs' rate limiters. For a plain count: Update 4 endpoints.
• PR titles: Refactor the worker's retry logic (one worker) vs Standardize the workers' retry logic (all of them). Never worker's when you just mean several workers.
• Slack standups: “All the tests are green” — not “test’s”. “It’s deployed” (it is) vs “its config changed” (the config belonging to it).
• Code comments: // the cache stores its own TTL — possessive, no apostrophe. A wrong it's here survives forever in the codebase.
• Bug reports: “The endpoint returns 500s” (plural of a number, no apostrophe). “The server’s response is malformed” (possessive).

Drills

Fix the sentence, fill the blank, or choose A or B. (Answers below — don’t peek.)

1. Fix: i merged 5 PR's and closed 3 ticket's today
2. Choose: The build failed because (A) its (B) it’s missing a dependency.
3. Choose: We should cache (A) its (B) it’s response to cut latency.
4. Fill the blank: All three ______ (microservice) share one database.
5. Fix: the developers commits broke the pipeline (you mean several developers)
6. Fix: i fixed so much typo in the docs
7. Choose: The queue lost (A) its (B) it’s ordering after the restart.
8. Fill the blank: We migrated all the ______ (legacy API) last quarter.
9. Fix: the server log's are full of 500's
10. Choose: (A) Its (B) It’s been flaky since the 2020s.
11. Fix: the team decision is final and the user's data is safe (the decision belongs to the team; data belongs to many users)
12. Fill the blank: I ran the ______ (query) against two ______ (index).

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Answer key

1. I merged 5 PRs and closed 3 tickets today. — Capital I; plain plurals take no apostrophe.
2. B — it’s. “It is missing a dependency” expands cleanly, so use it’s.
3. A — its. The response belongs to it → possessive its, no apostrophe.
4. microservices. Plural of a regular noun — add -s.
5. The developers’ commits broke the pipeline. — Several developers → plural possessive, apostrophe after the -s.
6. I fixed so many typos in the docs. — Typos are countable → many + plural -s; capital I.
7. A — its. “The queue lost it is ordering”? No — the ordering belongs to it → its.
8. legacy APIs. Acronym plural — just -s, never API's.
9. The server’s logs are full of 500s. — Logs belong to the server (server's); logs is plural so use are; plural of a number (500s) has no apostrophe.
10. B — It’s. “It has been flaky” / “It is” expands → it’s; and 2020s (decade plural) takes no apostrophe.
11. The team’s decision is final and the users’ data is safe. — team's (one team owns it); users' (data belonging to many users → apostrophe after the -s).
12. queries / indexes. “query” → -ies (consonant + y); “index” → indexes (or indices) is irregular.

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Part of the Developer English course — see 00-index.md.