Must and may
Have to, don't have to, may and must not.
Japanese says "must" with a double negative, "if you don't, it won't do", and "may" with "even if you do, it's fine".
| Meaning | Pattern | Example |
|---|---|---|
| Must | なければならない | 行かなければならない。 |
| Don't have to | なくてもいい | 行かなくてもいい。 |
| May | てもいい | 行ってもいい。 |
| Must not | てはいけない | 行ってはいけない。 |
Must
Change the final ない of the ない form to なければ and add ならない or いけない. なくては works the same way. In speech these get shortened.
| Form | Style |
|---|---|
| 行かなければなりません | Polite |
| 行かなければならない | Plain; common in writing |
| 行かなければいけない | Plain; common in speech |
| 行かなくてはいけない | Plain; common in speech |
| 行かなきゃ | Casual |
| 行かなくちゃ | Casual |
| 行かないと | Casual |
- Ashita wa hayaku okinakereba narimasen.I have to get up early tomorrow.
- Mō kaeranakya.I have to go home now.
Don't have to
- Ashita wa konakute mo ii desu.You don't have to come tomorrow.
May
The て form + もいい gives or asks for permission. てもかまいません is a more formal way to say it.
- Mado o akete mo ii desu ka.May I open the window?
- Hai, dōzo.Yes, go ahead.
Must not
The て form + はいけない, or more casually はだめ. In speech, ては becomes ちゃ and では becomes じゃ: 見ちゃだめ, 飲んじゃだめ.
- Koko de tabako o sutte wa ikemasen.You mustn't smoke here.
- Micha dame.Don't look.
Cards from this guide
8 cardsEach card asks about one thing this guide teaches, and its back gives the answer with why and an example. They're reviewed with the rest of the Verbs cards.
How do you turn 行かない (not go) into 'must go'?
行かなければならない (or 行かなければいけない)
なければならない or なければいけない: which is more common in everyday speech?
なければいけない
What's the usual casual way to say 'must go' (行かなければならない)?
行かなきゃ (also 行かなくちゃ or 行かないと)
What pattern after the ない form means 'don't have to'?
なくてもいい, as in 来なくてもいい.
How do you ask for permission to do something, such as opening the window?
The て form + もいいですか: 開けてもいいですか.
What's a more formal way to say てもいい (may)?
てもかまいません
How do you say 'must not', as in 'you mustn't smoke here'?
The て form + はいけない: 吸ってはいけない.
In casual speech, what does ては shrink to in 'must not', as in 見てはだめ (don't look)?
ちゃ: 見ちゃだめ.