为什么是用were而不是was?

为什么是用were而不是was? If I were you 中为什么是were而不是am或was He speaks English as though he were an American.为什么是he were而不是he was there was no more buses这句话中为什么是was而不是were if i were invited tonight ,i would go to the dinner party 为什么用 WERE这句话为什么是IF I WERE而不是 IF I WAS 如果我是你用英语怎么说?为什么是IF I WERE YOU而不是IF I WAS YOU哪? If I were you 中为什么是用were 而不是用was 如果是固定搭配,那么还有多少这样的搭配啊啊 为什么是How was your last school trip而不是How were your last school It ____ Jack and Mary who helped me the other day.为什么是was,而不是were? 为什么是if only I were you 而不是if only i was you 有一首歌,为什么是lf i were a boy,而不是lf i was a boy IF I WAS YOUR VAMPIRE关于这首歌的歌名为什么是I WAS而不是I WERE呢? 为什么是if I was your boyfriend而不是if I were your boyfriend?按理说虚拟语气应该都是用were,永远都不会出现was .那为什么JB的《Boyfriend》里用的是if I was your boyfriend? 为什么是I wish I were a bird 而不是I wish I was a bird是因为是虚拟语气,所以才这样用吗? Were you at home 7.00 this morning?No i was running with my sister 为什么是running而不是ran什么情况下用ran He talks as if he were the head of the office.为什么此处是用were而不是was?在看1000句,英语太烂,到了这句不明白为什么是he were the head而不是he was the head. Were you at home 7.00 this morning?No i was running with my sister 为什么是running而不是ran 为什么是Half of his money (was found) in the found and lost case?而不是were found?