なければならない details
write + must do
kaka nakereba naranai
must do; have to do
meaning: must write
宿題、今日じゅうに終わらせなきゃ。
shukudai, kyoujuu ni owarasenakya.
I've gotta finish my homework by the end of today. casual
日本では車は左側を走らなければならない。
nihon de wa kuruma wa hidarigawa o hashira nakereba naranai.
In Japan, cars must drive on the left. neutral
- contraction
- colloquial
- past
- polite
Examples
must do; have to — obligation stated as a rule or necessity
宿題、今日じゅうに終わらせなきゃ。
shukudai, kyoujuu ni owarasenakya.
I've gotta finish my homework by the end of today. casual
日本では車は左側を走らなければならない。
nihon de wa kuruma wa hidarigawa o hashiranakerebanaranai.
In Japan, cars must drive on the left. neutral
申込書は金曜日までに提出しなければなりません。
moushikomisho wa kin'youbi made ni teishutsushinakerebanarimasen.
The application form must be submitted by Friday. formal
Formation
{V-nai-stem}なければならないattaches to ない-stem
Variant notes
- なきゃ — なければ→なきゃ in speech, tail usually dropped entirely — もう行[い]かなきゃ。
- なければいけない — ならない swapped for いけない — warmer and more spoken; favored for personal rather than rule-like obligation
Notes
Related patterns
Similar
べきだ argues from principle and stays a disputable opinion; なければならない reports a requirement imposed by rules or circumstances — advice you may reject versus compulsion you may not.
なければならない reads stiffer and more written; ないといけない is the everyday spoken default.
なければならない states plain necessity and lives at every register; ざるを得ない is written and formal, and always concedes reluctance — circumstances, not duty, force the act, so 認めざるを得ない admits under pressure where 認めなければならない merely cites obligation.
Opposite
- なくてもいいnegated-obligation
なければならない obliges the act ("must do"); なくてもいい waives it ("need not do") — the natural answer to 行かなければなりませんか is 行かなくてもいいです.
Lookalikes
Both mandate the same act and share the ならない/いけない tails; only the fronts differ, and blending them at recall speed yields non-words like なくれば — learn なければ and なくては as unsplittable wholes.