现在分词表示这个动作的发起者是它修饰的词；比如：the dog biting the thief,biting指的是那只狗在咬；过去分词应该是指被动关系，注意这种结构本身是没有完成的意思.比如：the castle captured by the British被英国人占领的城堡动词不定式表示要发生的事情.比如：the case to be judged要被判的案子如果要表示完成，直接用时间状语就可以，或者用having done.比如：the student having finished the homework已经做完了作业的学生注意这种结构是属于现在分词的；或者the castle captured in 1977在1977年被占领的城堡。
1、The student who answered the question was John.
2、The boy whom you are talking to is my brother.
3、People who take physical exercise live longer.
4、I still remember the day when my brother joined the army.
5、He changed his mind,which made me very angry.
6、I'd like a room whose window looks out over the sea.
7、The weather in Beijing is colder than that in Guangzhou.
8、People in the world play basketball.
9、The city of New York is very large.
10、He looked at the street full of cars.
11、Italian is a Language very difficult to learn.
12、She has a garden much larger than yours.
13、The built a highway leading into the mountains.
14、We met a group of pupils returning from school.
15、What's the language spoken in that area?