Changing y to i

The tricky letter y

The letter y at the end of a word can be tricky. Sometimes it stays the same, and sometimes it changes to i when we add an ending. There is a simple rule to help you decide!

The y to i rule

Look at the letter just before the y.

• If it is a consonant, change y to i, then add the ending.
• If it is a vowel, keep the y.

Changing y to i

When a consonant comes before the y, swap y for i.

• baby → babies 👶
• puppy → puppies 🐶
• fly → flies 🪰
• cry → cried 😢
• happy → happily 😄
• carry → carried 🧺

Notice we add -es for plurals and -ed or -ly for other endings.

Keeping the y

When a vowel (a, e, i, o, u) comes before the y, keep it just as it is.

• boy → boys 👦
• toy → toys 🧸
• day → days ☀️
• key → keys 🔑
• monkey → monkeys 🐒

A handy table

Word	Letter before y	Change?	New word
baby	b (consonant)	y → i	babies 👶
happy	p (consonant)	y → i	happily 😄
toy	o (vowel)	keep y	toys 🧸
key	e (vowel)	keep y	keys 🔑

One special tip

Before -ing, the y always stays, even after a consonant:

• cry → crying 😢
• fly → flying ✈️

We never write two i's together!

Brilliant spelling!

Now you can decide when y becomes i. Look at the letter before the y, and you will always get it right.

Next, try Plurals: Adding -s and -es and Dropping the e Before Suffixes.