助動詞have的用法和例句

have作為助動詞可以：

1.構(gòu)成完成時態(tài)(have+過去分詞)： What has happened? 出了什么事? He told me Jane had left． 他告訴我簡已經(jīng)走了。 She will have arrived by this time tomorrow. 明天這時她就會到了。 How long have you been there? 你在那里待了多久?

2．構(gòu)成完成進(jìn)行時態(tài)（have+been+現(xiàn)在分詞) We have been trying to contact you． 我們一直在想和你聯(lián)系。 She has been teaching there for thirty years． 她在那里任教達(dá)三十年。 That was the book he had been looking for. 這是他一直在找的書。

另外，have (got)to還可構(gòu)成謂語，表示“不得不”： We have(got)to be careful． 我們得小心。 You don’t have to worry． 你不必憂慮。