“should”的用法

情态动词should意为“应当;应该”,可用以表达:1. 询问对方的意愿;2. 职责和义务; 3. 命令或建议。如:

Should I open the window?

He should do some work, but he doesn’t want to.

You should be careful next time.

should没有人称和数的变化,其后跟动词原形。如:

You should see a doctor at once.

She should take more exercise.

We / They should drink milk every day.

should的否定式是在should后面加not,可以缩写为shouldn’t,意为“不应当;不应该”。如:

You should not / shouldn’t work on the computer all day.

含有should的一般疑问句是将should提至主语前;其简略回答分别为“Yes,
主语(人称代词)+should.”和“No,主语(人称代词)+shouldn’t.”。如:

—Should I put another spoon of salt into the soup?

—Yes, you should. / No, you shouldn’t.