Apostrophes for Possession and Contraction — Explained Simply

Apostrophes cause more genuine confusion than almost any other punctuation mark — for children and plenty of adults too. There are really only two main jobs an apostrophe does, and once that's clear, most mistakes disappear.

Job one: contraction (missing letters)

An apostrophe shows where letters have been removed when two words are squashed together: do not → don't, it is → it's, they are → they're. The apostrophe sits exactly where the missing letter(s) would have been.

Job two: possession (belonging to someone)

An apostrophe also shows something belongs to someone: the dog's bone (the bone belongs to the dog). This is where most mistakes happen, so here's the full breakdown:

• One owner: apostrophe + s — "the girl's book" (belongs to one girl)
• Multiple owners, already ending in s: just an apostrophe — "the girls' books" (belongs to several girls)
• Multiple owners, not ending in s: apostrophe + s — "the children's books" (children doesn't end in s)

The classic mistake: it's versus its

This one trips up adults constantly, not just children. It's always means "it is" or "it has" (contraction). Its (no apostrophe) shows possession — "the dog wagged its tail." This is genuinely the one exception where possession doesn't use an apostrophe, which is exactly why it's the most commonly tested apostrophe rule at KS2.

A simple test that works every time

If you can replace the word with "it is" and the sentence still makes sense, use it's. If not, use its. "The dog wagged it is tail" doesn't make sense — so it's "its."

Practising this at home

Rather than drilling the rule abstractly, spot apostrophes together in whatever your child is reading, and ask "is that showing something belongs to someone, or is it two words squashed together?" Identifying the job the apostrophe is doing builds far more reliable understanding than memorising rules in isolation.