〜ても〜なくてもいい

Pattern: 〜ても〜なくてもいい
Level: N4
Reading: なくてもいい
Meaning: it's okay whether you ... or not
Attaches to: verb-て form
Nuance & register: Grants permission to omit an action.
Example: 明日来なくてもいいですよ。 You don't have to come tomorrow.