1、be certain/ be sure的用法1、be certain/ be surebe uncertain about意思是“对不确定（没把握）”uncertain的词根是certain,意思是“确信的，有把握的”，常用于以下结构： (1)be certain(sure) to do sth.“肯定会做”（表示某事将要发生）。如：He is certain(sure) to come next Sunday.(2)be certain(sure) of/ about sth.“确信、有把握”（表示某个人的思想状态）。如：We are certain/ sure of victory.(3)
2、名词从句作主语时，一般多用certain.It is certain that he will come.2、be different from 与不同Your idea is different from mine. 你的想法和我的不同。对比：make sb./ sth. different from使某人/某物不同于Her special accent makes her different from others. 她特殊的口音使她与众不同。3、be familiar with/be familiar tobe familiar with的主语是有生命的事，意为“某人对人、事熟悉”；be
3、 familiar to 的主语是无生命的事物，意为“某人/事为某人所熟悉”，对比:He is very familiar with the names of plants in English.他很熟悉植物的英语名称。Suzhou and Hangzhou are familiar to many foreigners.苏州和杭州为许多外国人所熟悉。Im not familiar with European history./European history is not familiar to me.我对欧洲历史不太熟悉。注意：be familiar with/to 还表示“精通、通晓”如：French is as familiar to him as English.他对法语就象对英语一样精通。 一句多译这些事实是每个学生都熟悉的。她精通4种语言。Key:These facts are familiar to every schoolboy./Every shoolboy is familiar with these facts.She is familiar with four languages./Four languages are familiar to her.
