なければいけない
Must do, Have to do
Structure
Verb［
Explanation
Similar to なくてはいけない, the phrase なければいけない expresses a strong sense of obligation or necessity. It is essentially a double negative, literally meaning 'if one does not do (A), it is not good/acceptable'. In simpler terms, it communicates that something 'must be done'.
This grammar pattern is formed by taking the negative form of a verb (ending in ない), changing ない to its conditional ば form, which results in なければ (if not). Then, いけない (it's not okay/it won't do) is appended to complete the phrase.
- 明日までにこのレポートを出さなければいけない。I have to hand in this report by tomorrow. (Not handing it in is not an option)
- 家の中では靴を脱がなければいけない。You must take your shoes off inside the house. (Not taking them off is improper)
In casual conversation, なければ is often contracted to なきゃ, which you may have seen in the なきゃ lesson. This shortened form can be used by itself or followed by いけない.
- あ、牛乳がない。スーパーに買いに行かなきゃ。Oh, we're out of milk. I gotta go buy some at the supermarket.
- もうすぐテストがあるから、勉強しなきゃいけないんだ。I have a test soon, so I have to study.
Caution
Although いけない (it's not okay) and ならない (it won't do) carry very similar meanings of necessity, ならない is generally reserved for more formal contexts or written language. Consequently, you will encounter いけない far more often in everyday spoken Japanese (when the ending is not dropped entirely).
Examples
図書館に本を返さなければいけない。
I have to return the book to the library.
飛行機に乗ったら、携帯電話の電源を切らなければいけません。
When you get on a plane, you have to turn off your cell phone.
薬はまずいけど、飲まなければいけません。
The medicine tastes bad, but I must drink it.
宿題がたくさんあるから、始めなければいけない。
I have a lot of homework, so I must start.
歯医者さんに行きたくないけど、行かなければいけません。
I don't want to go to the dentist, but I must go.
お客さんが来るので、部屋をきれいにしなければいけない。
Guests are coming over, so I have to clean the room.
先生にもっと漢字を勉強しなければいけないと言われました。
The teacher told me I have to study more kanji.
お腹が痛くて、トイレに行かなければいけない。
My stomach hurts, so I have to go to the bathroom.
明日までにこの書類を読めるようにしておかなければいけない。
I have to (finish) reading this document so that I'm ready by tomorrow.
明日は朝早いから、もう寝なければいけない。
I have to be up early tomorrow, so I must go to bed now.
赤ちゃんが寝ているから、静かにしていなければいけない。
The baby is sleeping, so we must be quiet.
エレベーターが壊れていたから、階段を使わなければいけなかった。
The elevator was broken, so I had to use the stairs.