不得不

bùdébù

adverb HSK 3 #1,088

Meanings

Double negation: 'cannot not' = 'must/have to.'

下雨了，我不得不带伞。

Xiàyǔ le, wǒ bùdébù dài sǎn.

It's raining, I have to bring an umbrella.

他不得不放弃了。

Tā bùdébù fàngqì le.

He had no choice but to give up.

为了赚钱，他不得不加班。

Wèile zhuàn qián, tā bùdébù jiābān.

To earn money, he has to work overtime.

grammar

不得不 emphasizes reluctance — you HAVE to do it even though you'd rather not. Compare with 必须 which is neutral obligation.

memory

Think of it as 'can't NOT do' — a double negative making a strong positive.

不 bù

得 de