1.Over / above

"Over"和"above"这两个介词的意思是在…….上面。“我们可以说(1)The sky is above our heads,也可以说(2)The sky is over our heads.我们也可以说(3)He Spread his handkerchief over his face.但不能说*(4)He spread his handkerchief above his face. 同样的，可以说(5)John has travelled all over the world以及 (6)The King reigns over a great empire，但是(5)和(6)里的 "over"却不可以"above"取代。

2.bring / take

"Bring"和"take"的意思相同，但用法并不一样。

"Bring"指东西向说话的人的方向去，如：

Bring me the book, please.

"Take"指东西向说话的人离去，如：

Take the dictionary away from me .

由此可见，"bring"和"take"都表示东西要移动，只是方向不同："bring"向说话者而来;"take"向说话者而去。

3.Certain / sure

"Certain"和"sure"都含“确定”之意，只是在句中的用法有些不同。下列第九到十一的句子都对，但第十二的句子就不行了：

(9) We are certain to come to the party. / Tom is sure to come today.

(10) I am not certain whether I will be able to do it. / Are you sure that you will do it?

(11) It is certain that Jason will leave me.

*(12) It is sure that Jason will leave me.

4. rob / Steal

虽然这两个字都是及物动词，但用法不同，不可互相取代。

"Steal"的宾语通常是被偷的东西，如“钱，手表”之类。"Rob" 的宾语必须是“人”或“地方”。如：

(13) A thief entered her house and stole her valuables.

(14) A stranger robbed a passer-by.

(15) Who robbed the bank last night?

5.chase / follow

这两个动词，一个是“追逐”，另一个是“跟随”，都是人家在前，他在后，但用起来不一样;"chase"不但是动词，也是名词，如：

(16)The cat chased the mouse and caught it soon after.

(17)The puplis followed the teacher to the classroom.

(18)There was a thrilling car chase in the film.

(19) Social unrest follows widespread unemployment.

(20) I could not follow what he was saying.