不 (bù)vs没 (méi)

Both mean "not", but one is for present/future and states, while the other is for past actions and "have".

不 (bù)

Used for present, future, habits, states (adjectives), and ALWAYS with 是.

没 (méi)

Used for actions that didn't happen in the past, and ALWAYS with 有.

Feature不 (bù)没 (méi)
TimeframePresent / Future / HabitsPast
ExceptionsAlways used with 是 (不是)Always used with 有 (没有)

translateCompare Examples

我明天不去。

Wǒ míngtiān bù qù.

I won't go tomorrow.

Future action.

我昨天没去。

Wǒ zuótiān méi qù.

I didn't go yesterday.

Past action.