The Most Abused Punctuation Mark
The Apostrophe Rules
Singular Possessive: Add 's
The student's book (one student). The teacher's desk (one teacher). James's car (names ending in s — add 's, though James' is also accepted). The child's toy. Always: noun + 's = one owner.
Regular Plural Possessive: Add '
The students' books (multiple students). The teachers' lounge (multiple teachers). The dogs' park. If the plural already ends in s, just add the apostrophe AFTER the s. No extra s needed.
Irregular Plural Possessive: Add 's
The children's toys. The women's room. The people's choice. Irregular plurals (that don't end in s) get the same treatment as singular: add 's. Because the plural doesn't end in s, the 's ending signals possession.
Its vs It's: The Great Trap
IT'S = it is / it has (contraction). 'It's raining.' ITS = belonging to it (possessive). 'The dog wagged its tail.' NO apostrophe for possessive. Think of: his, hers, ours, its — none of these possessive pronouns use apostrophes.
Teacher Tip
“Possessive pronouns NEVER use apostrophes: his (not hi's), hers (not her's), yours (not your's), ours (not our's), theirs (not their's), its (not it's for possession). When students see this pattern, 'its' as the possessive form makes perfect sense — it follows the same rule as every other possessive pronoun. If you can replace it with 'his' or 'her' and it works, use ITS (no apostrophe). If you can replace it with 'it is', use IT'S (with apostrophe).”
Frequently Asked Questions
When do I use an apostrophe for possession?
add
For singular nouns: add 's (the teacher's book). For regular plurals ending in s: add just an apostrophe (the teachers' lounge). For irregular plurals not ending in s: add 's (the children's toys). Never use an apostrophe for regular plurals that aren't possessive: 'tomatoes' not 'tomato's.'
What is the difference between its and it's?
add
IT'S (with apostrophe) = it is / it has: 'It's raining,' 'It's been a long day.' ITS (no apostrophe) = belonging to it: 'The cat licked its paw.' Test: replace with 'it is.' If the sentence works, use it's. If not, use its.
How do I teach apostrophes to ESL students?
add
Teach possessive and contraction apostrophes as two separate systems. For possession, use the three rules: singular 's, plural s', irregular plural 's. For its/it's, teach the pronoun parallel (his, hers, its — no apostrophe for possession). Practice with error-correction exercises from real-world examples.