not……until……句型的转换三法

not...until...句型，可以用 when 或者 after 引导的时间状语来做句型转换

比如：

I didn't get off until the bus got to the terminal station.

= When the bus got to the terminal station, I got off.

=I got off after the bus got to the terminal station.

直到汽车到达终点站，我才下车。

注意，否定句中until常常可以和before意思相似，所以也可用before互换。

I didn't get off until/before the bus got to the terminal station.

直到汽车到达终点站，我才下车。

Most children do not start school until/before they are six years old.

大多数孩子六岁才开始上学。