应该叫助动词.
英语中的助动词有以下这些：
1、 be been being am are is was were ;
2,have has had having ;
3,shall will shoud would ;
4,do does did ;
这些助动词一般没有意义,主要帮助构成谓语,表示时态、语态、语气等.或构成疑问及否定形式.
但有些助动词如shall ,will ,shoud ,would ,有时有一定的词义,作用接近情态动词,这时很难说它是情态动词还是助动词.