一、compare与contrast的误用
我们先从两者的定义入手来看两者的区别。 Compare的定义为：to examine people or things to see how they are similar or different. Contrast的定义为：to compare two or more things to show the difference between them.由定义不难看出前者侧重于找到两个或多个事物的异同，而后者则侧重于它们的不同。
看个例句：It is interesting to compare their situations to ours./It is interesting to contrast their situations to ours.
前一句翻译为：对比一下我们的情况与他们的情况会很有趣。
后一句的翻译为：我们的情况与他们的情况有很大的不同，这很有趣。
再看一个引自OXFORD ADBANCED LEARNER’S DICTIONARY的例子：
There is an obvious contrast between the culture of East and West.
The company lost $7 million in contrast to a profit of $6.2 million a year earlier.
When you look at their new system， ours seems very old-fashioned by contrast.
不难发现，Compare翻译为“与。。。相比”而contrast可译为“明显不同的是。。。”，切记这种翻译方式就不会用错彼此了。
二、介词使用错误
1、普通介词的误用
一般表现为固定搭配错误，如常把provide sb with sth用成provide sb sth; be satisfied with用成be satisfied for等等，虽然这样的错误看似无伤大雅，但在考官眼里就是影响顺畅阅读的，当然会影响最终成绩。解决的办法简单而古老：把常见的固定搭配牢记于心，问题自然就解决了。
2、 “to”作为介词的误用
“to”最常见的用法是以动词不定式符号的形式出现的，所以同学们也已经习惯了“to do”的固定搭配。对于一些如walk to me， to the left等介词to表方向等常见用法一般也不会出现错误。但是对于与动词搭配的介词to就会经常犯错：
如：More and more students have taken to depend on their parents to make decision for them.
这里的‘take to’ means ‘to begin to do sth as a habit’其中‘to’为介词，所以后面只能接名词或相当于名词的词，如动名词。所以黑体处应改为“depending on”。“take to”的另一个常用用法也需要牢记：
He hasn’t taken to his new school. (这里‘take to’ means ‘to start liking sb or sth’)
Prefer A to B中的“to”也是介词，会有prefer doing sth to doing sth/ prefer sth to sth else，这里朗阁海外考试研究中心提醒您，“prefer to do sth rather than do sth”中的“to”可是真正的不定式符号。
类似的常用用法请同学们牢记：
Be used to doing
Be accustomed to doing
See to doing
Adapt to doing
Adjust to doing
prefer doing sth. to doing sth.
等等，请注意平时仔细积累。
三、assume及claim使用不够准确
我们知道，think，assume，claim是议论文中常用引出观点的动词。在实际作文中，同学们往往认为几个词的意思是一样的，完全可以代换，所以拿过来就用。甚至还有同学把consider也拿过来与之混用。我们首先还是从定义来看这几个词的不同：
Think： to have opinion or belief about sth.
翻译为“认为”，通常接宾语从句来表达比较确定的观点。
Assume： to think or accept that sth is true but without having proof of it.
翻译为“假设、假定”，是否有事实依据是不确定的。
Claim： to say sth is true although it has not been proved and other people may not believe it.
翻译为“声称”，用这个词往往意味着不赞同紧跟其后的观点，所以很少用作‘I claim that…
