时间从句
　　1． 引导时间从句常用到下列词或词组：

　　　 a. 用从属连词 when(ever), while, as, before, after, since, ever since, till, until, once, now(that), as long as, as soon as 等引导，如：
　　　　　After / When we had finished tea we all began to dance.
　　　　　I'll call you as soon as I get there.

　　　　b. 有 as soon as 意义的副词，如 immediately, instantly, directly 等，如：
　　　　　Immediately / Instantly the button is pressed, the mine explodes.

　　　　c. 某些表示时间的名词词组，如 the moment / minute / instant (= as soon as), every / each time (= whenever), the day, the year 等，如：
　　　　　The moment / minute / instant the boy saw his mother, he stopped crying.
　　　　　Every / Each time Mother came to see me, she would bring me something to eat.
　　　　　He got ill the day he came back.

　　　　d. 一些意为“一…就”的关连从属连词，如 no sooner … than, hardly / scarcely / barely … when 等，no sooner, hardly，barely 置于句首时要用倒装结构，如：
　　　　　I had no sooner reached home than the telephone rang.
　　　　　= No sooner had I reached home than the telephone rang.

　　2． 时间从句常可转化成下列结构：
　　　　a. 分词短语或分词的独立结构，如：
　　　　　　When we arrived (= Arriving) at the station, we found the train gone.
　　　　　　After the task was finished (= The task finished), we went to the bathroom right away.

　　　　b. “on + V-ing” 结构，如：
　　　　　　As he stepped (= On stepping) out of the car he was seized by two men.

　　　　c. 时间从句的主语和主句主语相同而谓语是复合谓语时，可把从句的主语和连系动词省去，转化成连词引导的分词、名词、形容词、介词等短语，如：
　　　　　　While (I was) waiting at the station, I read the newspaper.
　　　　　　When (he was) still a boy he wrote some short poems.
　　　　　　When (they are) ripe, these apples are sweet.
　　　　　　They had an accident while (they were) on their way to the factory.

　　地点从句
　　通常由从属连词 where 和 wherever 引导，如：
　　　　Where there is a will there is a way.
　　　　Wherever they went, they were warmly welcomed.