they 是人称代词,属于第三人称,是复数形式.they 是主格,在句子中作主语.例如：They are good friends.They have finished their work.they 的宾格是them,形容词性物主代词是their,名词性物主代词是theirs.英语第三人...准确表述是：them是宾格，做介词或动词的宾语，置于他们后面，不一定都在结尾。