用before或after连接过去的两个句子时,before 和after各用什么时态

一：after引导的句子,一般用完成时,而主句用过去时.如：After I had finished my dinner,John came to my house.
二：after,before 前后句所用的时态,那就说明这两个词应该是连词,引导时间状语从句．
after conj.(时间)后,在后,在…之后,后于,迟于：
eg.
1.I played computer games after I had finished my homework.做完功课后,我玩电玩．(从句的动作发生在主句的动作前,因此,主句用一般过去式,从句用过去完成时．)
2.Please tell her I'll comeafter I do some shopping.(在含有时间状语从句和条件状语从句的复合句中,主句用一般将来时,从句用一般现在时)
before conj.
(1) 早于,在前,(时间上)在…之前,在…以前
(2) (与其)…不如,与其…(宁愿…),(宁可…而)不愿…,(宁愿)…也不
(3) 要不然；要不；否则
eg.
1.It will be a long time before we meet again.等到再一次见面,将会是一段很长的时间.(在含有时间状语从句和条件状语从句的复合句中,主句用一般将来时,从句用一般现在时)
2.We had started before day broke.在天亮前我们就已经出发了．
(主句用过去完成时,从句用一般现在时．表示主句的动作发生在从句动作之前．)