なければならない
Must do, Have to do
Structure
Verb［
Explanation
Similar to なければいけない, the structure なければならない conveys a strong sense of obligation, meaning that something 'must be done'. It's helpful to understand this grammar as a double negative, literally meaning 'if (A) is not done, it will not become (acceptable)', which simplifies to 'one cannot fail to do (A)'.
To form this grammar point, you start with the ない-form of a verb. You then change the final い to its conditional ば form, creating なければ (if not). Finally, you attach ならない (to not become) to complete the expression.
- 日本語を勉強しなければならない。I must study Japanese.
- 試験に合格したかったら、漢字を覚えなければならない。If you want to pass the exam, you must memorize the kanji.
As covered in the なきゃ grammar point, なければ is often shortened to なきゃ in casual speech. This abbreviated form is very common and can be used with or without ならない at the end.
- もうすぐ映画が始まるから、急がなきゃ。The movie is starting soon, so I have to hurry.
- 明日、友達が遊びに来るから部屋を掃除しなきゃならない。A friend is coming over tomorrow, so I have to clean my room.
Caution
Although いけない (cannot go) and ならない (will not become) express a similar meaning of necessity, ならない carries a more objective and formal nuance. For this reason, it is often found in written language or formal settings, whereas いけない (or its omission) is far more common in everyday spoken Japanese.
Examples
毎日この薬を飲まなければならない。
I have to take this medicine every day.
明日早く起きるから、もう寝なければならない。
I'm getting up early tomorrow, so I have to go to bed now.
海外旅行に行きたいなら、パスポートを申請しなければならない。
If you want to travel abroad, you have to apply for a passport.
来週、残業しなければならないかもしれない。
I might have to work overtime next week.
痩せたいから、毎日運動をしなければならない。
I want to lose weight, so I have to exercise every day.
気分が乗らない時でも、約束は守らなければならない。
Even when you don't feel like it, you must keep your promises.
失敗しても、諦めずに前に進まなければならない。
Even if you fail, you have to move forward without giving up.
しまった！会議の資料を印刷しなければならなかった。
Oh, shoot! I was supposed to print the materials for the meeting.
プロジェクトを成功させるために、チーム全員で協力しなければならない。
To make this project a success, the entire team must work together.
そろそろ暗くなるから、電気を点けなければならない。
It's getting dark, so I have to turn on the lights.
大学に合格できるように、もっと頑張らなければならない。
I have to try harder so I can get into university.
財布を忘れたから、友達にお金を借りなければならなかった。
I forgot my wallet, so I had to borrow money from a friend.