5)Every time, each time等也可以引 导时间状语从句
Every time I caught a cold , I had pain in my head. .
连接词before的小结：
1. We had sailed four days and four nights before we saw land. “……才”
句状 语 从
状语从句
时间状语从句 地点状语从句 原因状语从句 目的状语从句 结果状语从句 条件状语从句 方式状语从句 让步状语从句 比较状语从句
.
1.时间状语从句
1)由连词when, while, as, as soon as, before, after, since, till/ until 等引导。
his work.
注意: not until 在句首时要倒装
Not until he saw it himself did he
believe it.
.
4)表示“一…就…”的句型
(1)as soon as, once, the moment/ minute/ second, immediately/ directly/ instantly
2. We hadn’t run a mile before he felt tired. “不到……就”
4. Before I could get in a word, he had measured me. “还没来得及”
It will be a long time before…
2.be doing… when…
3.had done… when…
e.g.
We were about to start when it began to rain.
I was playing computer games when mom
came in.ile I was walking down the street, I came across an old friend. ( while =__w__h_e_n_) ②He likes pop music, while I am fond of folk music. ( while but ③While I really don’t like art, I find his work impressive. (while=__a_lt_h_o_u_g_h___)
.
另外, when/while还作并列连词,连接并列分句,
while表示 “而,可是”如:
I like reading while my wife enjoys watching TV. when表示 “就在这时” 在下列结构中，表示某
件事正在发生或刚刚发生，另一动作同时发生。
1.be about to do… when…
.
We were about to leave____ it began to rain. 2. She thought I was talking about her son, ____, in fact, I was talking about my son. 3. Hardly had I finished my composition ____ the bell rang.
On arriving at the station, the thief was arrested. On his arrival in Paris, he was recognized as a famous person.
.
(3)no sooner… than/ hardly… when / scarcely… when No sooner had they reached home than it started to rain. Hardly had I entered the room when the telephone rang.
As soon as he comes, I’ll tell him. The moment I saw him, I recognized him. I left immediately the clock struck 5.
(2)on / upon doing / on (upon) one’s +n
• 主句用将来时，从句常用一般现在 时表将来
I will tell him when he comes back.
.
2)while, when, as辨析
While引导的时间状语从句只指一段时间， 强调某一段时间内，主从句动作同时发 生。从句动词常是延续性的
When既可以指一个时间点,也可以是一段 时间，可表示主从句的动作同时或先后 发生。从句动词可以是延续性的，也可 以是非延续性的。
As强调主句﹑从句动作相并发生,译为”一 边…一边…”
.
When he returned , his wife was cooking. While he was reading, his wife was cooking. He hurried home, looking behind as he went .
A. when B. while C. as D. during
.
3)until/till(不用于句首)
“延续的动词（肯定式）+until ”表示 “直到…为止”
I waited for him until he came back. “非延续性动词（否定式）+until ”表示 “直到┅才”
He didn’t go to bed until he finished
.
对比训练 1 ____ he heard this, he got very angry. 2. I met Lucy____ I was walking along the river. 3. ____ a child, he lived in the countryside.
A. when B. while C. as