Section Ⅳ　Grammar & Writing

　　　　　　　　　　　　　　　　　情态动词(Ⅱ)

　　阅读下列句子，体会黑体部分用法

　　1．By now his restaurant ought to be full of people.

　　2．What could have happened?

　　3．Something terrible must have happened if Li Chang was not coming to eat in his restaurant as he always did.

　　4．Perhaps he would be able to earn his living after all and not have to close his restaurant.

　　1．ought to

　　(1)表示责任和义务，意为"应该"，与should同义，但语气比should重，侧重于"责任、义务、道德、法律"等方面。

　　You ought to work harder than your brother.

　　你应该比你哥哥更努力地学习。

　　[名师点津]　

　　ought to的否定形式为ought not to(oughtn't to)；一般疑问形式是将ought提至句首，其否定答语通常用don't have to或needn't。

　　-Ought he to see the doctor?

　　--他该去看医生吗？

　　-Yes，he ought to./No，he doesn't have to.

--是的，他该去。/不，他不必去。