Expressing External Obligation in Japanese with 〜なければならない
Learn to say you 'have to' do something in Japanese using 〜なければならない, and understand how it differs from personal 'must' by focusing on obligations imposed by others or circumstances.
By TheaFirst conversations · Yapr Learn
In Japanese, to express that you have to do something because of an external obligation—such as work, rules, or social expectations—you use the pattern 〜なければならない (nakereba naranai). This is different from simply wanting to do something or being told to do something. For example, 'I have to work tomorrow' becomes 明日は働かなければなりません (Ashita wa hatarakanakereba narimasen). In this lesson, you will learn how to form this pattern with verbs, how to adjust politeness, and when to use it instead of other obligation expressions.
By the end, you can…
- form the 〜なければならない pattern with different verbs.
- use 〜なければならない to express external obligations in polite and casual speech.
- distinguish 〜なければならない from other ways to express necessity or advice.
Listen once. Try it slowly. Then say it without looking.
Checking available voices…
明日は働かなければなりません。
I have to work tomorrow.
Ashita wa hatarakanakereba narimasen.
Polite form; used when speaking to a superior or in formal situations.
毎日、薬を飲まなければならない。
I have to take medicine every day.
Mainichi, kusuri o nomanakereba naranai.
Casual form; used with friends or family.
レポートを書かなければならない。
I have to write a report.
Repōto o kakanakereba naranai.
External obligation from school or work.
日曜日までに返さなければなりません。
I have to return it by Sunday.
Nichiyōbi made ni kaesanakereba narimasen.
Deadline obligation; polite form.
もっと勉強しなければならない。
I have to study more.
Motto benkyō shinakereba naranai.
Self-imposed obligation, but often due to external expectations.
Pronunciation guides are approximate. Slow playback keeps the original pitch.
Make it make sense
Useful pattern
To form 〜なければならない, take the negative stem of a verb (the ない form without ない) and add なければならない. For example, 働く (hataraku) becomes 働かない (hatarakanai), then 働かなければならない (hatarakanakereba naranai). For polite speech, replace ならない with なりません (narimasen). For する verbs, use しなければならない (shinakereba naranai). For 来る, use 来なければならない (konakereba naranai).
When to use it
Use 〜なければならない when the obligation comes from outside yourself: rules, laws, social norms, or someone else's request. For example, 会社の規則だから、制服を着なければなりません (Kaisha no kisoku da kara, seifuku o kinakereba narimasen) means 'Because it's company rules, I have to wear a uniform.' If you want to express a personal decision or advice, other patterns like 〜たほうがいい (ta hō ga ii) are better. Also, in casual conversation, 〜なきゃ (nakya) is a common contraction.
Listen to each line, then take one part and reply out loud.
明日、仕事に行かなければなりません。
I have to go to work tomorrow.Ashita, shigoto ni ikanakereba narimasen.大変ですね。何時に起きなければなりませんか。
That's tough. What time do you have to get up?Taihen desu ne. Nanji ni okinakereba narimasen ka.六時に起きなければなりません。
I have to get up at six.Rokuji ni okinakereba narimasen.早いですね。頑張ってください。
That's early. Do your best.Hayai desu ne. Ganbatte kudasai.A little context goes a long way
In Japanese, expressing obligation with 〜なければならない can sound strong or stiff. In casual conversation, people often use 〜なきゃ (nakya) or 〜ないと (nai to) to soften the tone. For example, 明日は働かなきゃ (Ashita wa hatarakanakya) is more natural among friends. However, in formal writing or business settings, the full form is expected.
One thing to watch for
Using 〜なければならない for a personal desire, like 'I want to eat sushi.'
Try this instead: 〜なければならない means 'have to,' not 'want to.' For desire, use 〜たい (tai): 寿司を食べたい (Sushi o tabetai). Use 〜なければならない only for obligations, e.g., 寿司を食べなければならない (Sushi o tabenakereba naranai) means 'I have to eat sushi' (e.g., because it's polite to accept).
Your turn
Try answering out loud before checking a possible answer.
1How do you say 'I have to study Japanese' in polite Japanese?
Show a sample answer
日本語を勉強しなければなりません。
This uses the polite form 〜なければなりません with the verb 勉強する (benkyō suru). The casual form would be 勉強しなければならない.
2Change 飲まなければならない (nomanakereba naranai) to polite form.
Show a sample answer
飲まなければなりません。
Replace ならない with なりません. The meaning remains 'have to drink,' but it becomes polite.
3What is a common casual contraction of 〜なければならない?
Show a sample answer
〜なきゃ (nakya) or 〜ないと (nai to).
Both are used in casual speech. For example, 行かなきゃ (ikanakya) means 'I have to go.' These are less formal but very common.
Use 〜なければならない (or 〜なければなりません) to express obligations imposed by external circumstances. Remember to adjust politeness and consider casual contractions in everyday speech.
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