1979年带一群美国客人去杭州都锦生丝织厂参观，入会议室，闻一位译员正巧说到 Several years ago our factory was quite infamous。见在座外宾无不愕然，见状，此译员马上改口：Several years ago our factory was quite unknown to the public.举座竟然爆发一阵笑声。此君不知infamous的含义不是“不知的”，而是“臭名昭著的”。

此事给我们的启迪是：in-未必总是否定前缀。又如：

a. different (not the same) 不同的

b. indifferent (not interested in, not caring about) 冷淡的，漠不关心的

1/ He was a different man from what he was 10 years ago.

他和十年之前相比已判若两人。

2/ People from different countries may not be able to understand each other, but after a game on the sports field they often become good friends. 

来自不同国家的人们也许不会相互了解，但在运动场上的一场比赛后他们常成为好朋友。

3/ I was so excited to see snow that I was indifferent to the cold.

见到雪我兴奋极了，全然不顾寒冷。

4/ They feel no warmth towards comrades and the people but are cold, indifferent and apathetic.

他们对同志对人民不是满腔热忱，而是冷冷清清，漠不关心、麻木不仁。

a. flammable (easily set on fire) 易燃的

b. inflammable (same as flammable: easily set on fire) 易燃的

1/ Cotton is flammable. 棉花易燃。

2/ The firemen succeeded in confining the outbreak (of the fire) to warehouses containing less inflammable materials. 

消防队员们成功地控制了火势，不让它向存有较易燃材料的仓库蔓延。

英语中含否定意义的前缀除in-之外，常见的尚有un-和dis-，关于这两个否定前缀，同样存在若干需谨慎对待的问题。

一、若干词的前缀可以是un-，也可以是dis-，但含义不一。

1. able的反义词是unable。

I'm unable to go to France this year, so you must go alone. 

今年我不能去法国，你得单独去。

disable系动词，含义是“使残废，使受损”（make unable to do sth.）。

He was disabled in the war and now has an artificial leg. 

他在战争中致残，现装一只假肢。

2. interested的反义词是uninterested。

He is uninterested in maths. 

他对数学不感兴趣。

disinterested的含义是“无私心的”(not influenced by personal feelings or interests)。

His action was not disinterested because he hoped to make money out of the affair.

他的行动并非无私，他想通过此事赚钱。

二、若干多义的词，其否定前缀仅构成其中一义的反义。

1. easy 的主要含义是：a. 容易的， b. 安逸的， c.（心境）平静的

uneasy与上面的释义之三构成反义，意为“心神不安”，“忧心忡忡”（anxious and worried）。

Their mother was uneasy about the children who were playing near the edge of the cliff.

孩子们在悬崖边玩耍，母亲心急如焚。

2. 动词own的主要含义有：a. 拥有， b. 同意  c. 承认是……的主人

disown仅与释义之三构成反义，意为“否认……同自己有关系”（say that one has no connection with）。

The boy was so wicked that his father disowned him.

这男孩太顽劣，父亲否认了与他的关系。

3. like (v. 喜欢)与like (prep. 象)各有不同的前缀。

She’s very unlike (prep.) her mother.

她很不象她母亲。

I dislike (v.) being spoken to like that.

我不喜欢别人那样同我交谈。

最后值得一提的是valuable与invaluable，前者的含义是“宝贵值钱的”（of great value, worth or use），后者的意思是“非常珍贵的”（of value too high to be measured）。两者实为近义词，但后者比前者在程度上要强。它们的反义词是valueless或worthless。

We are much obliged to you for your valuable help. 

对于你给我们的宝贵帮助，我们真是非常感激。

Honest and faithful friends are an invaluable jewel.

    诚实忠诚的朋友是无价之宝。

The smuggler with some invaluable curios was caught at the Customs. 

那个带有一些贵重古玩的走私分子在海关被抓获。