过去时中为什么可以用after?如he came back after two weeks我觉得把after换成would不也可以么?

过去时中为什么可以用after?如he came back after two weeks我觉得把after换成would不也可以么? He couldn't understand spoke English before he moved to Canada.为什么speak和move用过去时?一句话中不是只有谓语动词表现时态就可以了么?为什么speak和move都要用过去时? after为什么可以用在动词过去式之后表示一段时间之后?They got there after three weeks．这个句子应该是将来时,为什么动词用过去时? 为什么after常用于过去时? 什么情况下复合句(如While I was watching TV,he came in)中两个句子用过去进行时? after的从句,主句用过去时,从句用什么 to do 可以作介宾的宾补吗 为什么可以用过去分词. when he ( )the door ,he found his keys were nowhere.A.would open B.opened C.had opened D.was to open为什么答案选D,为什么不选B,在时间状语从句中,不是可以用过去时表过去将来时吗 After hearing the news,he fainted.为什么前面不用过去完成时态呢 请问句子中“for+一段时间”动词为什么可以用过去时 it happened after three days这个为什么用过去时呢? He will go back to his parents,because he left home for too long这句话中leave为什么用过去时?为什么不用一般现在时呢? after the alarm had been given,the great ship turned sharply to aboid a direct collision为什么after the alarm had been given要用过去完成时,直接用过去时不可以吗,而且given这里表达的是什么意思呢? after a minute后面为什么要过去时?什么意思 Now read how she felt after being in the hiding place since July .原句是过去时,after 和 since 为什么可以连用? after为什么有时候要用主将从现,如：After he gets back,he will do his homework.而有时候又不要用,如After I leave school,I want to visit Beijing.为什么,理由? 请教英语大师,为什么句子The man did not wake up until the bed had struck the bed和句子After he had put it on the floor,he went to sleep again.要用过去完成时呢?全篇都是用个过去时,为什么这两句不能用过去时?菜 after从句必用过去完成时吗?after i heard the news ,i got a surprise.（主,从句都是过去时）after i had heard the news ,i got a surprise（主,从句都是过去时）这样可以吗?