Work hard when (you are) young, or you'll regret.少壮不努力,老大徒伤悲。
b.连词+名词
While (he was) a young boy, he was always ready to help others.他在孩提时代就乐于助人。
Although (he was) a farmer, now he is a famous director.尽管他曾是个农民,而现在是位著名的导演了。
c.连词+现在分词
As (she was) walking along the river bank, she was singing a pop song.她沿着河堤边走边唱着流行歌曲。
Although (he is) doing his best in maths these days, he has still got no good marks.尽管近来他一直在学数学,但他仍然没有取得好成绩。
d.连词+过去分词
He won't go there with us unless (he is) invited.除非受到邀请,否则他不会和我们一道去那里。
The concert was a great success than (it was) expected.这场音乐会出乎意料地取得了巨大成功。
e.连词+不定式
He stood up as if (he were) to say something.当时他站起来好像要说什么。He wouldn't solve the problem even if (he were) to take charge.即使他来负责,他也解决不了这个问题。
f. 连词+介词短语
She looked anxious as though (she was) in trouble.她看上去很焦急,好像遇到了麻烦。
He had mastered the English language before (he was) in the USA.他到美国之前就懂英语了。
注意:当从句主语和主句主语不一致时,从句部分要么用完全形式,要么用独立主格结构来表达。例如:
When the meeting was over, all the people went out of the meeting-room.当会议结束时,人们都走出了会议室。(=The meeting over,
[编辑本段]一、时间状语从句
要点: 时间状语从句，由以下连词引导：
when while as after before as soon as since till /until by the time 在时间状语从句中，要注意时态一致。一般情况下主句是将来时的时候，从句要用一般现在时。
1.when当...的时候
Mozart started writing music when he was four years old.
(当)莫扎特4岁的时候，开始写音乐作品。
2.while当...时
He visited a lot of places while he was traveling.
他在旅途中参观了许多地方。
3.as在...的同时；一边...一边...
He smiled as he stood up.
他一边站起来一边笑着。
4.after在...之后
He left the classroom after he had finished his homework the other day.
前几天做完作业之后回的家。
5.before 在...之前
Mr. Brown had worked in a bank for a year before he came here.
布朗先生来这之前已经在一家银行里工作一年了。
6.as soon as 一...就...
We began to work as soon as we got there.
我们一到那就开始工作。
I will write to you as soon as I get home.
我一到家就给你写信。
7.since 自。。。以来 到现在
表示自过去的一个起点时间到目前(说话时间)为止的一段持续时间。主句一般用现在完成时，从句用一般过去时。
Mr Green has taught in that school since he came to China three years ago.
自格林先生来中国以来，他就在这所学校教书。liuxuepaper.com