did（一般過去時(shí)）,have（現(xiàn)在完成時(shí)）,do（一般現(xiàn)在時(shí)）,does（一般現(xiàn)在時(shí),主語為三單）,has（現(xiàn)在完成時(shí),主語為三單）,had (過去完成時(shí))這些詞都可以是助動(dòng)詞,用于不同時(shí)態(tài)的否定句和疑問句
另外,這些詞也可以是實(shí)義動(dòng)詞
做：do（一般現(xiàn)在時(shí))I do my homework every day.
does（一般現(xiàn)在時(shí),主語為三單）My mother does housework every day.
did（一般過去時(shí)）They did their best yesterday.
有：have（一般現(xiàn)在時(shí))I have a book.
has（一般現(xiàn)在時(shí),主語為三單)She has a pen.
had (一般過去時(shí))They had dinner at 7 yesterday.