副词的主要作用是作状语，可用来修饰：
1.动词：
Don't drive too fast.
开车不要太快。
They were warmly received.
他们受到热情的接待。
2.形容词：
You don't know how grateful we are to you.
你不知道我们多么感激你。
Her eyes were wide open.
她的眼睛睁得大大的。
3.副词：
How gracefully they are dancing!
他们跳得多美呀!
We are going too slowly.
我们进展太慢。
4.整个句子：
Frankly speaking，I don't think he can succeed.
坦白地说，我不相信他会成功。
Obviously，there is still much room for improvement.
显然还大有改进余地。
此外副词还可用作：
1.表语：
Mary was down with fever.
玛丽发烧了。
The daffodils are out.
水仙花开了。
许多表示位置的副词(如up，about，around，behind，in，round，back，away)都可以这样用。
2.定语：
I met her on my way home.
我是在回家的路上碰见她的。
This was my first day up.
这是我下床后的第一天。
有不少副词(如here，there，around，off，then)可以这样用。
3.复合宾语的一部分(即作宾语补语)：
Will you have him in?
请让他进来好吗?
I'm glad to see you back.
看你回来我很高兴。
