1. 到底何时使用did? did和其它助动词一样,本身无意义,自己不能独立作谓语,只能和其它主要动词一起构成谓语,用于构成一般过去时的否定句和疑问句,当然也常常用于代替上文中的行为动词的过去式。如: I didn't go to school last Sunday. 上周日我没上学。 Did you buy a new pen yesterday? 昨天你买了枝新钢笔吗?
2. did身后的动词到底用什么形式? 有的小朋友总不注意did身后的动词用什么形式,在否定句和疑问句中, did身后的动词必须用原形。 “他昨天没有在家吃午饭。” [误] He didn't had lunch at home yesterday. [正] He didn't have lunch at home yesterday.
3. 我能用be动词代替吗? 不管怎么说,含有行为(实义)动词的一般过去时的肯定句变成否定句或疑问句时,不能用be动词,必须用到did!含be动词的句子构成否定句或疑问句都绝不会让did露面! 例句:They went to the park last week. (改为否定句) [误] They weren't go to the park last week. [正] They didn't go to the park last week.