I. 徵求意見和請求 (May, Can, Could, Do you mind if…?)
II. 向別人要求 (Will, Can, Could, Would, Would you mind…?)
III. 勸告 (Should, Ought to, Had better)
IV. 給予建議 (Why don’t…?, Why not…?, Could, Let’s, How about…?)
V. 表達是否有能力 (Can, Could, Be able to)
VI. . 偏好 (Prefer, Would prefer, Would rather)
VII.   必要性 (Have [got] to, Must)  
VIII.   對…的期望 (Be supposed to)
IX.      對過去發生過的事情之建議用法 (should have, ought to have, could have, might have)
X.      對過去的推測 (must have, may have, cant have, etc.)
XI.     未來的可能性 (May, Might, Coud)
XII.    對現在的假想(推測) (May, Might, Could, Must, Have [got] to, Can't)  

（更上一層樓：通常請求不只包括一個問句，還有稱謂Form of address、開頭語Opening, 請求起頭Prerequest，理由Reasons，請求Request本身，詳見Requests 英文解說）

I.                    徵求他人同意或向他人請求 (May, Can, Could, Do you mind if…?)

A. 基本句型

 May I use your phone? Yes, you may (can)./No, you may not (can’t).

   Can/Could I write on this paper? Yes, you can (may)./No, you can’t (may not).*

*注意!

1)      May not不能像can’t寫成mayn’t.

2)      問句中可用May/Can/Could,然回答只能用may/may not和 can/can’t/cannot.

3)      May比Can和Could的用法稍正式些.

 B. 我們也常在句子中加入please:

    Could you drive slower, please?

    Could you please turn off the radio?

 C. “Do you mind if…”的用法:

    Joe: Do you mind if I sleep in this room? (你介意我睡在這一間嗎?)

    Daisy: Not at all. (一點也不.)/Sure./I don’t mind.*

*注意!

1)      用 “Do you mind if…” 是在怕打擾到他人而做的詢問

2)      注意這種句型的答案, e.g.

“Do you mind if I write on this paper?”

(允許) “Not at all. You can have it.”

(不允許) “Yes, I do. In fact, I need it for my calculus homework.”

 D. 在他人拒絕請求時, 1)可能會解釋拒絕的原因:

   Jane: Can I turn in my paper on Thursday?

   Prof.: I’m sorry. I don’t accept late papers.

2)若已有明文規定,請求則會被拒絕且不予解釋:

“Can I smoke in here?” “No, you can’t.”