1. *when 引导突然发生的动作，意为：正在那时…
we were eating when a friend came to see me. (我们正在吃饭，正在那时一个朋友来了)
2. *hardly/ scarcely/ barely …when 句式 ， 意为：一…….就….
no sooner …than
i had hardly fallen asleep when the telephone rang. 非倒装句 (我刚一睡着,电话铃就像了)
i had no sooner fallen asleep than the telephone rang.
hardly had i fallen asleep when the telephone rang. 倒装句
no sooner had i fallen asleep than the telephone rang.
3. while 1) 当…的时候
while 句子/while doing sth
they knocked at the door while/ when i was taking a bath
*2) (放在句中)而, 但是(强调前后两者的反差)
jane is fashionable while her sister’s clothes are often out-of-date.
while i admit the problem is difficult, i don’t agree they can’t be solved.
it won’t be long before everyone knows it./ it wasn’t long before everyone knew it.不久…
it was a week before he returned. 过了一周才…
**long before 区别before long
it wasn’t long before she quit smoking. 不久她就戒烟了
i expect the bus will be here before long. (before long = soon)
three years had passed before we knew it. 不知不觉三年过去了
do it before you forget. 趁着没忘先做.
the thief ran away before i had time to shout for help. 在我还没来得及求救之前,小偷跑了
5. since 自从,
it is two weeks since i came.
it was two weeks since i had come.
until 用于肯定句, 前面的动词要用持续动词; until 用于否定句, 前面的动词使瞬间动词
he didn’t leave until i returned.否定句用瞬间动词
keep waiting until he comes back.肯定句用持续动词
i didn’t go to bed until i finished homework. not until 的原始句型
not until i finished homework did i go to bed. not until 的倒装句型
it was not until i finished my homework that i went to bed. not until 的强调句型
7. **every time/ each time/next time/the minute/ the second/ the first time/ the moment 直接引导时间状语从句， 不加that或when
she is nervous every time she sees me.
the first time i saw her, i didn’t take it seriously.
the first time = when …for the first time
when i saw her for the first time, i was nervous.
cf. for the first time
last week, i went to the states for the first time.
8. unless = if not 如果不
9. as long as/ so long as/ on condition that 只要
10. even though/ even if 即使
11. **where 引导地点状语
where there is water , there is life.
plants grow well where there is plenty of water.\
don’t put the medicine where children can get it.