HSK 3
不A不B
bù A bù B
The Not-A-Not-B structure (不A不B)
Explanation
不A不B (bù A bù B) is a fixed four-character structure, used to express a state at a moderate, middling level — neither too much this way nor too much that way.
不 (bù = not) + A + 不 (bù) + B, in which A and B are usually a pair of ANTONYM adjectives (大 dà big / 小 xiǎo small; 冷 lěng cold / 热 rè hot).
When you want to praise or comment that something is just right, comfortable, reasonable (不大不小 = just the right size, 不冷不热 = pleasantly mild).
A and B must be a pair of antonyms for the meaning "just right" to come out; if you combine two words that aren't opposites, the structure loses its meaning.
Choosing A, B that aren't a pair of antonyms, or misreading this structure as a true negation ("not... not...") instead of the meaning "just right, middling".
Examples
neither big nor small (just right), neither long nor short, neither cold nor hot (mild), neither too much nor too little (just enough), neither early nor late (right on time)
Learn “不A不B” effectively
The grammar point “不A不B” (The Not-A-Not-B structure (不A不B)) is one of the key structures at HSK 3. To use it fluently, you need to understand the contexts where it's used and practice regularly.
Study tip: read the examples aloud many times to build a natural reflex. Then try making your own sentences for your own situations. Use the audio button to hear and practice accurate pronunciation.
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