なくてもいい

expression

need not; don't have to

Attaches to the negative stem of a verb or adjective to express lack of obligation or necessity. Very common in everyday speech.

• 今日きょうは残ざん業ぎょうしなくてもいいですよ。

  You don't have to work overtime today.

• そんなに急いそがなくてもいい。

  You don't need to hurry so much.

expression

need not have; need not exist

Used when saying that something does not need to be present or exist. Often appears in conditional or hypothetical contexts.

See also: ない

• 特とく別べつな道どう具ぐはなくてもいい。

  You don't need any special tools.

• 理り由ゆうがなくてもいいから、とにかくやってみよう。

  You don't need a reason; let's just give it a try.