if
[误] If it will rain I won't go to school tomorrow.
[正] If it rains I won't go to school tomorrow.
[析]由 if引起的状语从句要用一般时表示将来。
[误] I want to know if he comes here tomorrow.
[正] I want to know if he will come here tomorrow.
[析] if所引起的如果是宾语从句则不能用一般现在时表示将来。
[误] I want to know if it will rain tomorrow he will come or not.
[正] I want to know if it rains tomorrow he will come or not.
[析]这里的 if从句是整个宾语从句的条件状语，所以，还应用一般时表示将来。
ill
[误] He spent many years looking after his ill father.
[正] He spent many years looking after his sick father.
[析] ill和 sick都可以作表语，如： I'm ill (sick). 美国英语中常用 sick，而英国英语中两者都可用，但 ill一般不作定语。
in
[误] In a cold morning, I went to school alone.
[正] On a cold morning, I went to school alone.
[析]在 in the morning或 in the afternoon词组中，不论在这两个名词的前或后加任何修饰词，其介词 in都要变为 on.
[误] I will finish it after two days.
[正] I will finish it in two days.
[析]中文中几天以后可以完成，或几天后来取，在译为英文时都不要用 after，而要用 in.如： He will be back in a few days.
in into
作为副词应用 in，而不能用 into，如： Come in, please. 又若在句中不涉及到动词的位置，只是表达空间的位置时用 in，如： The teacher in the office is my mother. 但在 go, run, come, walk, dive等词后则要用 into. 如： She dives into the river.
instead
[误] The boy stayed in bed all day instead to go to school.
[正] The boy stayed in bed all day instead of going to school.
[析] instead of其后要接动名词、名词或代词，而不能用不定式，如： I choose this book instead of that one.
[误] The beer here is not good, so I drink wine instead of it.
[正] The beer here is not good, so I drink wine instead.
[析] instead是副词，而 instead of是介词短语。如： If you are not free, you may come another day instead.
interest
[误] He has a great interest for physics.
[正] He has a great interest in physics.
[误] He has some interest in many companies.
[正] He has some interests in many companies.
[析] interest作为"兴趣"讲可用作不可数名词，但作为"利息"、"股份"讲时为可数名词。?
[误] This is an interested book.
[正] This is an interesting book.
[析]修饰物时应用 interesting,如， an interesting film，而讲某人对某事感兴趣时要用过去分词 interested，如： I'm interested in this play. 但"他是一个十分有趣的人"。应译为 He is an interesting man. 所以 interesting是"令人感兴趣"之意，而 interested则表示某人对某事物感兴趣，多用" be interested in something"这一句型。
invent
[误] America was invented by Christopher Columbus in 1492.
[正] America was discovered by Christopher Columbus in 1492.
[析] invent意为"发现"即从无到有，如： Compass was invented by the Chinese people. 而 discover则意为"发现"。
