Expressing "Does not have to"

Genki I had a lesson on expressing "have to do" for verbs, as in "You have to eat breakfast." Well, now it's time to learn how to express "Does not have to."

To say this, take a negative plain form verb, drop the い in ない, and add くてもいい. This なくて is the negative て form, used in plenty of other grammar structures.

プレゼントをくれなくてもいいですよ。
You don't have to get me a present.

アリスは納豆がきらいだから、食べなくてもいいよ。
Alice hates natto, so she doesn't have to eat it.

病めてるから、学校に行かなくてもいいよ。
You're sick, so you don't have to go to school tomorrow.

This grammar can also be used with nouns and adjectives in the exact same way - remove the い from the ない in their negative form and add くてもいい.

ステージはすごくなくてもいいよ。
The performance doesn't have to be amazing.

クリスマスパーティードレスはきれいじゃなくてもいいですよ。
The dress for the Christmas party doesn't have to be pretty.

彼はベジタリアンじゃなくてもいいよ。
My boyfriend doesn't have to be a vegetarian.