have no choice but to; cannot but
HSK level
不得不 is written with 19 strokes (不: 4, 得: 11, 不: 4). The animation replays automatically.
不得不 (bùdébù) is an adverbial expression meaning 'have no choice but to / cannot but,' placed before a verb to say you are forced or compelled to do something you would rather not.
It is a double negative — literally 'not (不) able-to-not (得不)' — which resolves to a strong 'must, reluctantly.' The reluctance is the key nuance that separates it from neutral 必须 (must) or 得 (have to): 不得不 stresses that circumstances leave you no other option, often against your wishes: 天太晚了，我不得不走 (it's too late, I have no choice but to leave).
English speakers should read the double negative not as 'do not have to' but as an emphatic 'have to.' It highlights external pressure rather than internal obligation or rule-following.
Note: Neutral; common in both speech and writing to stress reluctant necessity. Slightly more emphatic than plain 得 or 必须.
Character by character
Memory hook: 'Not able to not' do it — the double 不 cancels out into a reluctant 'I have to.'
太晚了，我不得不回家。
Tài wǎn le, wǒ bùdébù huí jiā.
It's too late; I have no choice but to go home.
spoken
因为下雨，比赛不得不取消。
Yīnwèi xià yǔ, bǐsài bùdébù qǔxiāo.
Because of the rain, the match had to be canceled.
neutral
我不得不承认，他说得对。
Wǒ bùdébù chéngrèn, tā shuō de duì.
I have to admit he's right.
neutral
为了照顾家人，她不得不放弃了工作。
Wèile zhàogù jiārén, tā bùdébù fàngqì le gōngzuò.
To take care of her family, she was forced to give up her job.
written
只好 means 'have no choice but to / can only,' very close to 不得不. 只好 points to settling for the one remaining option; 不得不 stresses being compelled. Both express reluctance, but 只好 feels like 'the only way left,' 不得不 like 'forced to.'
不用 means 'need not / don't have to' — the opposite of obligation. Learners sometimes misread 不得不 (a double negative meaning 'must') as if it lessened obligation; it does the reverse. 不得不去 = have to go; 不用去 = don't have to go.
Acquire it by listening
Fluentide turns real news into Chinese listening at your exact level, so words like 不得不 show up again and again in natural sentences — with pinyin and translation every time. No flashcards. Free to start.
