until 表示“直到”，表示动作一直持续到某个时间点，常与延续性动词连用；

not ... until表示“直到...才”，表示动作直到某个时间点才会发生，否则不发生，常与短暂性动词连用。

He slept（延续性动词）until 10 o'clock. 他一直睡到十点。（十点之前都在睡）

He did not wake（短暂性动词） up until 10 o'clock. 我直到十点才醒。（十点之前都没醒）

I'll stay（延续性动词）here until the rain stops. 我会呆在这儿直到雨停。（动作stay一直持续到雨停）

I won't leave（短暂性动词）until I finish my work.我不完成工作就不走。（动作leave在完成工作前都没发生）

You should wait until your mother comes back.（略）

You shouldn’t leave until you mother comes back.（略）

-How soon will the football match start? -Not until half past eight.

It is difficult for us to learn a lesson in life until we've actually had that lesson.

until /not...until 引导时间状语从句，时态规律:主将从现（主句一般将来时，从句一般现在时）；主过从过（主句一般过去时，从句一般过去时）。

She looked after the sick girl until she woke up. 她照顾生病的小女孩直到她醒来。

That writer didn't become famous until his novel was published. 那个作家直到出版了他的小说才变有名。

小练习：

-Did you hear the rain?

-______________________

A. Until 30 minutes.

B. Until 30 minutes later

C. Not until 30 minutes

D. Not until 30 minutes later