南開(kāi)中學(xué) 李士明

　　CORRECT USAGE OF TENSES OF THE PREDICATES

　　如何學(xué)好情態(tài)動(dòng)詞

　　(Modal verbs)

　　can: 從客觀角度陳述人們都了解的客觀事實(shí)

　　can 表示客觀能力, 與先天、后天能力無(wú)關(guān)。

　　Birds can fly up into the sky easily.

　　鳥(niǎo)兒可以輕易地飛到天上去。

　　Luke can speak Chinese very fluently.

　　魯克的漢語(yǔ)說(shuō)得很流利。

　　can表示人人都了解的客觀可能性或聽(tīng)話人已知的客觀事實(shí)。

　　If you are brave enough, all difficulties can be overcome.

　　如果你不畏艱險(xiǎn)，所有的困難都一定會(huì)克服。

　　Correct ideas can be transformed into a material force that changes the world.

　　正確的理念一定能夠轉(zhuǎn)化為改變世界的物質(zhì)力量。

　　I hear that you are going to Thailand. It can be dangerous to be there, I think.

　　聽(tīng)說(shuō)你要去泰國(guó)，我看到那兒去挺危險(xiǎn)的。

　　may: 表示說(shuō)聽(tīng)雙方均不確切，相當(dāng)于I am not sure

　　推測(cè)或了解可能性

　　The man you are looking for may be in that room.

　　May I have a talk with you?

　　He may never succeed without your help.

　　基于may自身的不確定性，常置于句首，用來(lái)表示祝愿

　　May success attend you! 祝你成功！

　　(May) God bless you! 愿上帝保佑你！

　　You can/may come at any time. (口語(yǔ)中can和may從不同含義角度均可使用。)

　　ought to: 從客觀角度表示安排、責(zé)任或義務(wù)

　　You ought to do the cleaning after school because you are on duty.

　　你放學(xué)后應(yīng)該做衛(wèi)生，因?yàn)榻裉炷阒等铡?/p>

　　You ought not to write so carelessly.

　　(It is the students’ responsibility.學(xué)生應(yīng)該做好的事)

　　Everybody should /ought to help each other in the study, shouldn’t / oughtn’t they?

　　(在反義疑問(wèn)句中should和ought to有時(shí)可以前后交叉使用，起到主客觀互補(bǔ)的作用)