关于haveto和willhavetohaveto本身就能用来表示将来,如：Wehavetoleaveearlytomorrow请问willhaveto和haveto用法有什么不同,用来表示将来什么时候要加will,什么时候不用

Question

关于have to 和will have to
have to本身就能用来表示将来,如：We have to leave early tomorrow
请问will have to和have to用法有什么不同,用来表示将来什么时候要加will,什么时候不用

Answer 1

will have to是have to 的将来式.
I’ll have to...=It will be necessary for me to...
i.e.It will be necessary for them to pass a special test.=They will have to pass a special test.
be able to
　　a.位于助动词后.
　　b.情态动词后.
　　c.表示过去某时刻动作时.
　　d.用于句首表示条件.
　　e.表示成功地做了某事时,只能用was/were able to,不能用could.
　　He was able to flee Europe before the war broke out.
　　= He managed to flee Europe before the war broke out.