Saying what you have to do in Japanese

Level A2

Saying what you have to do in Japanese

It's Friday afternoon and you're new at work: do you have to come in tomorrow, and what time on Monday? In this lesson you say what you have to do and what you don't need to do, and you use both to give someone simple advice. Both patterns start from the ない form, so that's where we begin.

Recap: the ない form

The ない form is the plain negative: 行かない, "don't go". Among these five verbs, 行く, 飲む and 働く change their last sound to an "a" sound before ない (く → か, む → ま), and 食べる simply drops る. Two forms are new here: 働かない and 来ない. Watch out for 来る: 来ます is read きます, but 来ない is read こない. This table has no audio, so read each form aloud; you'll hear them inside the sentences below.

Dictionary formます formない form
行(い)く（いく）行きます（いきます）行かない（いかない）
飲(の)む（のむ）飲みます（のみます）飲まない（のまない）
働く（はたらく）働きます（はたらきます）働かない（はたらかない）
食(た)べる（たべる）食べます（たべます）食べない（たべない）
来(く)る（くる）来ます（きます）来ない（こない）

Model: Friday at work

Listen once without reading. A new employee asks the boss about the days ahead. Notice how a "no" answer changes the ending: the question has なければなりませんか and the answer has なくてもいいです. 仕事 is "work", and 八時 is read はちじ.

Saying you have to: 〜なければなりません

Take the ない form, remove ない and add なければなりません: 行かない → 行かなければなりません, "I have to go". Word for word it's close to "if I don't go, it won't do", which is why a sentence about doing something starts from a negative. Japanese usually leaves out who has to: in 八時に来なければなりません the boss means "you", and only the situation says so. The tone is firm, good for rules, schedules and your own duties, and か turns it into a question. With a colleague, a final よ adds a note of warning, and the situation can make the sentence sound like advice: 水を飲まなければなりませんよ; don't say it to a boss or a stranger, because it would sound pushy. In this lesson, treat that よ as part of these set sentences, since its uses come later; in the last example, ご飯 means "a meal".

行か／飲ま／食べなければなりません（か）

Saying you don't have to: 〜なくてもいいです

Change ない to なくて and add もいいです: 行かない → 行かなくてもいいです. This is the same もいいです that gives permission in 飲んでもいいです; here the permission is for not doing something, roughly "even not going is fine". 来 keeps its こ reading: 来なくて. Add か to ask to be let off: 土曜日は行かなくてもいいですか. To reassure someone, use the set sentence 今日は働かなくてもいいですよ; 全部 means "all of it".

行かなくて／飲まなくて／食べなくてもいいです（か）

Have to, no need, may, must not

To answer "no" to 働かなければなりませんか, you switch patterns: いいえ、働かなくてもいいです, not a negative of なければなりません.

The last four sentences show one verb and one place, a café: 飲まなければなりません says you have to drink it here, 飲まなくてもいいです says there's no need to, 飲んでもいいです says you may, and 飲んではいけません says you must not. Keep "don't have to" and "must not" apart, just as in English: 〜なくてもいいです leaves the choice to you, while 〜てはいけません forbids. And 明日は来ません（きません） is neither of them: it only says you aren't coming.

Just to recognize: なきゃ in conversation

Among friends and family you'll hear a shorter ending: 行かなきゃ, "I've got to go". なきゃ comes from なければ, goes in the same place, and usually the sentence simply stops there. These sentences are only for recognizing: at work and with people you don't know, keep using 〜なければなりません.

Your turn, and the summary

Imagine a colleague who never stops working. Cover the lines below. Ask in their place whether they have to work on Saturday too, answer that they don't, and then advise them that they do have to eat; the は in ご飯は sets the meal against the work, like 水は and コーヒーは when you compared rules. Only then check (without よ the sentence is still right). If you try another verb or another day, even better. In short: the ない form without ない + なければなりません says you have to, and ない → なくて + もいいです says you don't have to, which never means you must not.

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