不得不

bùdébù

adverb HSK 3 #1,088

Meanings

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

HSK 4

下雨了，我不得不带伞。

Xiàyǔ le, wǒ bùdébù dài sǎn.

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

HSK 5

他不得不放弃了。

Tā bùdébù fàngqì le.

He had no choice but to give up.

HSK 6

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