Must / Have to

Vocabulary

()べるた・べるru-verbto eat
()い・くu-verbto go
勉強(べんきょう)べん・きょうstudy
()ね・るru-verbto sleep
(はたら)はたら・くu-verbto work
()きるお・きるru-verbto wake up
(かえ)かえ・るu-verbto return home
(はや)はや・いi-adjearly
明日(あした)あしたtomorrow

There is no single word for “must” in Japanese. Instead, you use a double negative phrase that literally means “If I don’t do X, it won’t be good.”

Structure 1: なければならない

The most formal and standard way.

  1. Conjugate to Negative (ない form).
  2. Drop い and add ければ.
  3. Add ならない (will not become/be good).
()べなければならない。Must eat.
勉強(べんきょう)しなければならない。Must study.
明日(あした)(はや)()きなければならない。I must wake up early tomorrow.

Structure 2: なくてはいけない

Slightly less formal, “It cannot go if I don’t…”

()べなくてはいけない。Must eat.
宿題(しゅくだい)をしなくてはいけない。Must do homework.
もう(かえ)らなくてはいけない。I have to go home now.

Casual Abbreviations

In speech, these long phrases are shortened.

  • なくちゃ (from なくては)
  • なきゃ (from なければ)
もう()かなくちゃ。I gotta go now.
(はや)()なきゃ。I gotta sleep early.
勉強(べんきょう)しなきゃ。Gotta study.