When does y
change to i?

Happy becomes happiness, but play becomes played. One question tells you which.

Try a little practice ↓

THE RULES, ONE AT A TIME

Look at the word.
Then add the ending.

y → i

Consonant + y

happy → happiness

Change y to i before -ness, -ly, -er, -est, -ful and -ed.

easy → easily; funny → funnier; carry → carried

keep y

Vowel + y

play → played

A vowel before the y means the y stays.

enjoy → enjoyment; stay → staying

keep y

Suffix starts with i

study → studying

Keep the y before -ing and -ish so you don’t get “ii”.

cry → crying; baby → babyish

y → i

Plurals too

city → cities

Consonant + y also changes before -es.

baby → babies; story → stories

Exceptions to remember

Some common words break the rule: day → daily, pay → paid, say → said, lay → laid. Some short words keep the y: shy → shyness, dry → dryness.

A note for the grown-ups.

Rules summarised from the Department for Education’s English spelling appendix. Examples and practice are original site copy, checked against the ENABLE2K word list. Spelling rules have exceptions; check unfamiliar words in a dictionary.