一般现在时变为疑问句时,一般在句首加助动词do或does的方式构成,第三人称单数时用does,其余情况都用do,主要动词一概不变,用原形；在以have或has为主要动词的句子中,可以直接将动词have或has提前放于句首,也可以在句首加动词do或does构成,have或has一律用原形have.如：
Do you work?
Does he work?
Has she a cake?
Does she have a cake?