◊ Ought is almost always followed by to and the infinitive form of a verb. The phrase ought to has the same meaning as should and is used in the same ways, but it is less common and somewhat more formal. The negative forms ought not and oughtn't are often used without a following to.*ought后面几乎总是接带to的动词不定式。短语ought to与should的意思和用法相同，但ought to较不常用且更为正式。否定形式的ought not或oughtn't后面常不接to。