怀孕周期胎儿发育过程:when did you do that ?中do 为什么用原形不用过去式?

来源：百度文库编辑：杭州交通信息网时间：2024/04/28 13:20:58

you did that when这个是这句话的原来位置
转换成问句 be动词或助动词要提前
所以用did you do
did就是do 的助动词形式
比如：i had lunch at 8 o'clock
转换：did you have lunch at ..............?

did已经表示过去式了！

问句中不是有did 吗？！

did已经表示过去式了.do还原

前面有了助动词,后面的动词还原为原形

因为前面有did
在一句句子中，过去式后加原形

when did you do that ?中do 为什么用原形不用过去式? When did you go to school yesterday? ( ) Wath did you do last weekend What did you do on holiday Whai did you do on Chileren? When do you always brinking up？ When will you do 中文意思 what___you___(do) when I phoned you. when did you first read an english book 怎么回答 what did you do during the spring festial