2. 引导条件状语从句的从属连词。这类连词主要有if, unless, as [so] long as, in case 等。如：
Do you mind if I open the window?我开窗你不介意吧?
Don’t come unless I telephone. 除非我打电话，否则你别来。(from www.hxen.com)
As long as you’re happy，it doesn’t matter what you do. 只要你高兴，你做什么都没关系。
In case it rains they will stay at home. 万一下雨，他们就呆在家里。
注意：在条件状语从句中，通常要用一般现在时表示将来意义，而不能直接使用将来时态。不过，有时表示条件的 if之后可能用 will，但那不是将来时态, 而是表示意愿或委婉的请求(will为情态动词)。如：
If you will sit down for a few moments, I’ll tell the manager you’re here. 请稍坐, 我这就通知经理说您来了。
3. 引导目的状语从句的从属连词。主要的有 in order that, so that, in case, for fear等。如：
He raised his voice so that everyone could hear. 他提高了嗓音，以便每个人都能听见。
Take your umbrella (just) in case it rains. 带上雨伞，以防下雨。
She repeated the instructions slowly in order that he should understand. 她把那些指示慢慢重复了一遍好让他听明白。
4. 引导结果状语从句的从属连词。主要的有so that, so…that, such…that等。如：
I went to the lecture early so that I got a good seat. 我去听演讲去得很早, 所以找个好座位。
I had so many falls that I was black and blue all over. 我摔了许多跤，以致于全身都是青一块紫一块的。
He shut the window with such force that the glass broke. 他关窗子用力很大, 结果玻璃震破了。(from www.hxen.com)
5. 引导原因状语从句的从属连词。主要的有because, as, since, seeing (that), now (that), considering (that) 等。如：
He distrusted me because I was new. 他不信任我，因为我是新来的。
As you are sorry，I’ll forgive you. 既然你悔悟了，我就原谅你。
Since we’ve no money, we can’t buy it. 由于我们没钱，我们无法购买它。
Seeing that he’s ill he’s unlikely to come. 因为他病了，他大概不会来了。
Now that she has apologized, I am content. 既然她已经道了歉, 我也就满意了。