HSK 7-9
不A不B
bù A bù B
Neither A nor B
Structure
不 + Adjective/Verb (A) + 不 + Adjective/Verb (B)
How it works
The '不A不B' structure is a common four-character idiomatic pattern used to describe a middle state, a lack of specific qualities, or a sense of proportion. In many cases, A and B are antonyms (like big/small) to signify 'just right,' while in other cases, they are related terms used to express a negative or awkward quality.
Examples
这件衣服的大小不宽不窄，穿起来非常合身。
Zhè jiàn yīfu de dàxiǎo bù kuān bù zhǎi, chuān qǐlái fēicháng héshēn.
The size of this piece of clothing is neither too wide nor too narrow; it fits perfectly.
他这种不三不四的行为，让大家都感到很反感。
Tā zhè zhǒng bù sān bù sì de xíngwéi, ràng dàjiā dōu gǎndào hěn fǎngǎn.
His dubious and improper behavior makes everyone feel disgusted.
他的态度不卑不亢，赢得了在场所有人的尊重。
Tā de tàidù bù bēi bù kàng, yíngdéle zàichǎng suǒyǒu rén de zūnzhòng.
His attitude was neither cringing nor arrogant, winning the respect of everyone present.
Common mistakes
Using the structure with two unrelated adjectives that do not form a logical pair or a recognized Chengyu (idiom).
Tip
Many '不A不B' phrases are fixed Chengyu. Instead of inventing your own, try to memorize common ones like 不知不觉 (unconsciously) or 不屈不挠 (unyielding).
More HSK 7-9 grammar
See 不A不B in real Chinese
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