call

　　[误] Ill call at Mr Brown.

　　[正] Ill call on Mr Brown.

　　[误] Ill call on Mr Browns home.

　　[正] Ill call at Mr Browns home.

　　[析] 作拜访讲时，at后面接访问地点，而on后面接访问的人。

　　 call on drop in visit

　　call on比较正式的为公务的访问，如：We were called on by the old students. 而drop in则是比较随便的走走，顺便拜访，如：If youre free, drop in. 而visit则是更正式的外交访问或友好往来，如：My schools headmaster will visit America next week.?

　　can

　　[误] A blind man can not judge colours.

　　[正] A blind man cannot judge colours.

　　[误] I cannt call for you at ten.

　　[正] I cant call for you at ten.

　　[析] can的否定形式应为cannot或cant.

　　[误] Its only six oclock. That mustnt be the postman.

　　[正] Its only six oclock. That cant be the postman.

　　[析] must用来表示一种肯定的推断，如：She must have some problems. She keeps crying. 但在否定句中则要用cant， 要表示对过去的推测则要用must+have+过去分词的表达法，如：The lights have gone out.A fuse must have blown.而对过去的否定推测则多用?cant?+have+过去分词，如：I dont think he can have heard you. Call again.

　　[误] We could not help to laugh at once.

　　[正] We could not help laughing at once.

　　[正] We could not help but laugh at once.

　　[析] couldnt help+动名词表示禁不住做了某事。但could not help but与could not but后面要加不带to的不定式，意思都是不得不去做某事.如：You could not (help) but respect him.

　　can be able to

　　can与be able to都可以用来表示能力，但can只有现在时与过去时，be able to则可用任何时态，如：He will be able to teach the child. 但要表示经过努力而达到的一次性动作则只能用be able to，如：He finally was able to jump over 2?10 meters. 或：The plane was able to fly over the mountain. 但要注意的是这两个词都没有进行时态，而be able to后面不接不定式的被动态。

　　can could

　　can与could都可以用在现在时的口语中，只是用could更为礼貌，语气更委婉。如：Could you tell us a story

　　care

　　[误] I dont care coffee.

　　[正] I dont care for coffee.

　　[误] Take care for your steps.

　　[正] Take care of your steps.

　　[析] care for是对某物感兴趣，而care of是关心，要当心某事，如：She didnt care for him. Take care of what you are doing.

　　[误] I dont care where we will go if it doesnt rain.

　　[正] I dont care where we go if it doesnt rain.

　　[析] 在it doesnt matter, I dont care, I dont mind, 及in case引出的状语从句后面要用现在时表示将来。如：Ive got a football in case we have time for a game.

　　change

　　[误] I want to change my camera with that one.

　　[正] I want to change my camera for that one.

　　[析] change for为以某物为交换物。而change with则是随而变，如：The woods colour changed with the season.

　　cheap

　　[误] A teachers salary is generally very cheap.

　　[正] A teachers salary is generally very low.

　　[析] 工资的高低要用low，cheap是指价格便宜，如果要讲物美价廉则要用not expensive, 如：This car is not expensive.

　　choose

　　[误] We each had to have a choose of A or B.

　　[正] We each had to have a choice of A or B.

　　[析] choice是名词，而choose是动词。

　　class

　　[误] The class is watching TV.

　　[正] The class are watching TV.

　　[析] class作主语时，如果作为整体讲则应用单数形式的谓语动词，如：The class was more than forty in number. 如考虑到具体的每个成员时则应用复数形式的谓语动词，如：The class are, in general, very bright.

　　clean

　　[误] Sorry, I didnt bought it here. I cleanly forgot.

　　[正] Sorry, I didnt bought it here. I clean forgot.

　　[析] clean可以作为副词讲，其意为完全，而cleanly则意为正确地、干净利落地，如：The knife doesnt cut cleanly. 而clean作为形容词讲时意为清洁的、干净的，如：Her face is not clean now.

　　call

　　[误] Ill call at Mr Brown.

　　[正] Ill call on Mr Brown.

　　[误] Ill call on Mr Browns home.

　　[正] Ill call at Mr Browns home.

　　[析] 作拜访讲时，at后面接访问地点，而on后面接访问的人。

　　 call on drop in visit

　　call on比较正式的为公务的访问，如：We were called on by the old students. 而drop in则是比较随便的走走，顺便拜访，如：If youre free, drop in. 而visit则是更正式的外交访问或友好往来，如：My schools headmaster will visit America next week.?

　　can

　　[误] A blind man can not judge colours.

　　[正] A blind man cannot judge colours.

　　[误] I cannt call for you at ten.

　　[正] I cant call for you at ten.

　　[析] can的否定形式应为cannot或cant.

　　[误] Its only six oclock. That mustnt be the postman.

　　[正] Its only six oclock. That cant be the postman.

　　[析] must用来表示一种肯定的推断，如：She must have some problems. She keeps crying. 但在否定句中则要用cant， 要表示对过去的推测则要用must+have+过去分词的表达法，如：The lights have gone out.A fuse must have blown.而对过去的否定推测则多用?cant?+have+过去分词，如：I dont think he can have heard you. Call again.

　　[误] We could not help to laugh at once.

　　[正] We could not help laughing at once.

　　[正] We could not help but laugh at once.

　　[析] couldnt help+动名词表示禁不住做了某事。但could not help but与could not but后面要加不带to的不定式，意思都是不得不去做某事.如：You could not (help) but respect him.

　　can be able to

　　can与be able to都可以用来表示能力，但can只有现在时与过去时，be able to则可用任何时态，如：He will be able to teach the child. 但要表示经过努力而达到的一次性动作则只能用be able to，如：He finally was able to jump over 2?10 meters. 或：The plane was able to fly over the mountain. 但要注意的是这两个词都没有进行时态，而be able to后面不接不定式的被动态。

　　can could

　　can与could都可以用在现在时的口语中，只是用could更为礼貌，语气更委婉。如：Could you tell us a story

　　care

　　[误] I dont care coffee.

　　[正] I dont care for coffee.

　　[误] Take care for your steps.

　　[正] Take care of your steps.

　　[析] care for是对某物感兴趣，而care of是关心，要当心某事，如：She didnt care for him. Take care of what you are doing.

　　[误] I dont care where we will go if it doesnt rain.

　　[正] I dont care where we go if it doesnt rain.

　　[析] 在it doesnt matter, I dont care, I dont mind, 及in case引出的状语从句后面要用现在时表示将来。如：Ive got a football in case we have time for a game.

　　change

　　[误] I want to change my camera with that one.

　　[正] I want to change my camera for that one.

　　[析] change for为以某物为交换物。而change with则是随而变，如：The woods colour changed with the season.

　　cheap

　　[误] A teachers salary is generally very cheap.

　　[正] A teachers salary is generally very low.

　　[析] 工资的高低要用low，cheap是指价格便宜，如果要讲物美价廉则要用not expensive, 如：This car is not expensive.

　　choose

　　[误] We each had to have a choose of A or B.

　　[正] We each had to have a choice of A or B.

　　[析] choice是名词，而choose是动词。

　　class

　　[误] The class is watching TV.

　　[正] The class are watching TV.

　　[析] class作主语时，如果作为整体讲则应用单数形式的谓语动词，如：The class was more than forty in number. 如考虑到具体的每个成员时则应用复数形式的谓语动词，如：The class are, in general, very bright.

　　clean

　　[误] Sorry, I didnt bought it here. I cleanly forgot.

　　[正] Sorry, I didnt bought it here. I clean forgot.

　　[析] clean可以作为副词讲，其意为完全，而cleanly则意为正确地、干净利落地，如：The knife doesnt cut cleanly. 而clean作为形容词讲时意为清洁的、干净的，如：Her face is not clean now.