不 / 没 Explained

Why does Chinese have two words for “not”? Because 不 and 没 split a job English does with one word. The bu vs mei rule is one of the cleanest in Mandarin: 不 (bù) negates the present, future, habits and feelings — what you don’t or won’t do; 没 (méi) negates a completed or past action — something that didn’t happen. 我不喝咖啡 (“I don’t drink coffee”), 我没吃饭 (“I haven’t eaten”) — and 有 always takes 没. Get this split right and your Mandarin instantly sounds more native.

Two ways to say “not”: the bu vs mei split

English makes do with one “not”; Chinese uses two, and which you pick carries real information. 不 is subjective — it negates what you choose, feel or generally do, across the present and future. 没 is objective — it reports that an action didn’t happen. Master that one distinction and the bu vs mei choice becomes almost automatic.

不 (bù) — present, future & habits

不 is the first half of the bu vs mei pair, and your default “not”. It negates what you don’t do, won’t do, or aren’t: habits (我不喝咖啡, “I don’t drink coffee”), intentions and refusals (我不去, “I’m not going”), feelings and modal verbs (我不喜欢, 我不想, 不会), adjectives (不高, “not tall”), and 是 (我不是学生). It rules the present, the future and general truths — if you’re talking about now, later or always, reach for 不.

没 (méi) — what didn’t happen

没 — the other half of the bu vs mei pair, often written 没有 — negates a completed or past action: something that didn’t happen, or hasn’t happened yet. 我没吃饭 (“I haven’t eaten”), 他没来 (“he didn’t come”), 我没看过 (“I haven’t seen it”). One pairing rule matters: 没 and 了 never mix. 了 marks completion and 没 marks non-completion, so it’s 我没吃 — never 我没吃了. Whenever you’re reporting that something simply didn’t take place, use 没.

有 → always 没有

One verb ignores the present/past split completely: 有 (“to have / there is”). 有 is always negated with 没 — never 不. 我没有钱 (“I don’t have money”), 这里没有人 (“there’s nobody here”). 不有 is simply not a word in Mandarin. Whenever you negate 有 — past, present or future — it’s 没有, full stop.

Everyday sentences

Six bu vs mei sentences you’ll use constantly. The Chinese Grammar Wiki compares the two in more depth. Tap 🔊 to hear each.

Same verb, both negations

Plenty of verbs accept both 不 and 没 — and the choice changes the meaning. 他不去 means “he won’t go / isn’t going” (intention, present); 他没去 means “he didn’t go” (it didn’t happen). 你为什么不吃？ asks “why aren’t you eating?”, while 你为什么没吃？ asks “why didn’t you eat?”. The bu vs mei choice quietly encodes whether you mean present intention or a past non-event — so it’s worth a half-second’s thought.

The cousin: 别 (bié) — “don’t!”

The bu vs mei split covers statements, but commands have their own negator: 别 (bié), a quick, forceful contraction of 不要 meaning “don’t!”. 别走 (“don’t go”), 别说话 (“don’t talk”), 别担心 (“don’t worry”). The structure is simply 别 + verb (+ object). So: use 不 and 没 to say what isn’t or didn’t happen — and use 别 to tell someone not to do something.

The traps: 有 and 了

Two traps trip up almost every learner. The 有 trap: never negate 有 with 不 — 不有 isn’t a word; it’s always 没有. The 了 trap: 没 already means an action didn’t happen, so it can’t take the completion marker 了 — write 我没吃 (“I didn’t eat”), never 我没吃了. And remember a past action that didn’t happen needs 没, not 不: 昨天我没去 (“I didn’t go yesterday”), not 昨天我不去.

Three rules that make bu vs mei work

1. 不 = present, future, habits, feelings. Also adjectives and 是 — 我不喝咖啡, 我不是学生.
2. 没(有) = a completed or past action that didn’t happen. Never with 了 — 我没吃饭.
3. 有 is always negated with 没(有), never 不 — 我没有钱.

Five common mistakes, fixed

Quick check — bu vs mei

Pick the best answer for each: