英语从属连词用法分析
从引导状语从句的连词的意义来看，可分为引导时间、原因、结果、目的、让步、条件、方式、比较、地点等名种从句的连词。
（1）引导时间状语从句的从属连词
①此类连词主要有：when, while, after, before, as, as soon as , until, till, once, since, whenever, no sooner...than, hardly/barely/scarcely...when等。
When I got to the theatre, I found that they had sold all the tickets.当到达剧院时，我发现票已售完。
We should strike while the iron is hot.我们要趁热打铁。
Since he entered the university, he has made great progress in his studies.
They kept on working until it became dark.他们一直工作到天黑。
Once you begin , you must go on. 你一旦开始，就必须继续下去。
You seem to have a ready-made answer, whenever I ask you a question.
每逢我问你问题, 你总好象有现成的答案。
Now (that) you are here, you'd better stay.你既然来了，那就不要走了。
No sooner had they got to the field than it began to rain.他们刚到田里就开始下雨了。
Hardly had he set foot on his native land when he felt comfortable.
他一踏上祖国的土地就感到心情舒畅。
注意：no sooner, hardly等位于句首时需用倒装语序。
②every time, each time, next time, the last time, the moment, immediately等，引导句子其作用相当于一个时间状语从句。
She felt a thrill the moment she got into the theatre.她一进剧场就感到一种激动。
Every time he got to Beijing, he came to see me.每次他来北京，他都来看我。
（2）引导原因状语从句的从属连词
此类连词主要有because, as, since, now(that)，等。because引导的从句表示产生某种结果的必然的因果关系，语气较重，可回答why问句；since语气较轻，常位于句首；as则语气最轻。
We couldn't cross the river because the water had risen. 水已经上涨了，所以我们没能过河。
Since everyone is here, let's begin. 既然大家都来了，我们就开始吧。
I must stop writing now, as I have rather a lot of work to do.我必须停笔了，因为我还有许多工作要做。
Now that you've got a chance, you might as well make full use of it.
The Italian boy was regarded as a hero because he gave his life for the country.
Why use wood when you can use plastic? 既然能用塑料, 为什么还要用木料?
（3）引导让步状语从句的从属连词
此类连词主要有although, though, as, even if, even though, no matter what等。
Though my father is old, yet he wants to do something for our country.
我爸虽然老了，可他还要为国家做点事。
Even if there are difficulties， we must do it well. 即使有困难，我们也要把工作做好。
Young as I am, I know some of the family secrets. 尽管我年龄小，我知道一些家庭秘密。
Nobody believed him no matter what he said. 不管他说什么每人相信他。
Much as I have travelled, I have never seen anyone who’s as capable as John.
（4）引导条件状语从句的从属连词
此类连词主要有if, unless, as/so long as, supposing等。
If we go on polluting the world ,it won't be fit for to live in.如果我们继续污染这个世界，那这个世
界就会不适合我们生活了。
You will fail unless you work hard. 除非努力你才不会失败。
You can go out as/so long as you promise to be back soon. 只要你保证很快回来，你
就可以出去。
What shall we do supposing he won't agree? 假定他不同意，我们怎么办？
The WTO cannot live up to its name if it does not include a country that is home to one fifth of mankind．
如果世贸组织不能容纳占世界人口五分之一的国家，那它就名不符实。
You will be late unless you leave immediately. 如果你不马上走，你要迟到了。
Unless he comes, we won't be able to go. 他不来我们不能走。
（5）表示行为方式的从属连词
表示行为方式的从属连词主要有as，as if/though等。
When a pencil is partly in a glass of water, it looks as if it were broken.当把铅笔一部分放到水
里时，铅笔看上去就像断了。
We did as he told us. 我们照他叮嘱的做了。
He spoke as though he knew the question very well. 他说得好像对这个问题知道得很清楚。
注意：以as if引导的状语从句，其谓语动词常用虚拟语气。与现在相反的情况用过去时，与过去相反的情况用过去完成时。
I remember the whole thing as if it happened yesterday. 整个事情我都记得,就好像此事发
生在昨天。
He spoke like that as if he had been there before. 他那样说好像他从前去过那里似的。
（6）表示目的的从属连词
表示目的的从属连词主要有that, so that，in order that等。
I hurried so that I wouldn't be late for class. 为了上课不迟到我们赶紧走。
John shut everybody out of the kitchen so that he could prepare his grand surprise for the party.
约翰把大家关在厨房外边，是为了能够为晚会烹饪出人意料的饭菜。
John saved his money in order that he might buy a bicycle. 约翰为了买一辆自行车而把钱节
省下来。
