介词状语时什么成分

1.有几个概念你可能弄混了：介词是一个词语本身的性质；状语则是一个词语（词组）在一个完整表达的句子中所起的作用,充当的成分；
2.英语句子成分有主语,谓语,表语,宾语,宾语补足语,定语,状语等；
3.所谓的介词状语自然是句子中的“状语”成分,只是这个状语是有介词性质的词语来充当的；
4.修饰动词,形容词,副词以及全句的句子成分,叫做状语.用作状语的通常是副词,介词短语,不定式和从句等.
5.状语的功用：状语说明地点、时间、原因、目的、结果、条件、方向、程度、方式和伴随状况等.
6.a.副词一般在句子中做状语．
He speaks English very well.他英语说得非常好.
He is playing under the tree.中的under the tree(地点状语)
b.不定式在句子中可以作目的状语.
I come specially to see you.我专门来看你.
c.介词短语作状语
My parents often tell us about their bitter life in the past.
Ten years ago,She began to live in Dalian.
The boy was praised for his bravery.
d.从句作状语
When she was 12 years old,she began to live in Dalian.
If I am not busy tomorrow,I will play football with you.
e.分词作状语
Having had a quarrel with his wife,he left home in a bad temper.
Inhibited in one direction,it now seems that the Mississippi is about to take another.