also: なくちゃ
Used after the negative stem of a verb (ない-form minus ない) to mean 'without doing' or 'if not'. Often part of a conditional or negative obligation pattern.
If I don't eat breakfast, I won't have any energy.
Abbreviation of なくてはいけない or なくてはならない. Used after the negative stem of a verb to express obligation. Very common in casual speech, especially as なくちゃ.
See also: なくてはいけない
Nothing will start unless I meet him.
I have to go now.
I must do my homework.
Kanji spelling is uncommon; the kana form is strongly preferred.
Kanji spelling of the colloquial contraction; very rare.
From the negative continuative form なく (from ない) + particle て + topic particle は. The contracted form なくちゃ derives from なくては via regular sound change.