怎么分辨定语从句中的主谓宾?The man who you met yesterday is an actor.比如这个

如果你知道这是个定语从句,就把定语从句拿出来.
who you met yesterday,然后把引导词改为先行词
the man you met yesterday
然后把先行词放在合适的地方
you met the man yesterday（你就明白这个the man是宾语,主语是you)
又如：
The man who is standing there is my father.
who is standing there
the man is standing there(主语是the man,也就是引导词当主语了.）
The man whose brother is a teacher is now studying at college.
whose brother is a teacher
the man's brother is a teacher(这里就是引导词充当定语了）