英语的前缀dis-, in- 和un-均表示否定，它们分别和不同的词根结合在一起构成相应的反义词，如：approve赞成→ disapprove不赞成；active活跃的→inactive不活跃的；changeable可改变的→unchangeable不可改变的。一般来讲，任何一个词根和这三个前缀中哪一个前缀进行搭配都有它的习惯性和固定性，需要逐一记忆掌握。但有趣的是，英语中有几组派生词是由同一词根分别和这三个否定前缀进行不同的组合，其词义会发生不同的变化。这些词虽然不多，但较为常用，应引起我们格外的注意。

　　1. unable: adj. not able to do sth. 不能够；无法

　　He will be unable to get the railway station by 5:00.他无法在五点钟以前到达火车站。

　　disable: v. to make (a person) unable to use his body properly使残废

　　Carter was disabled in the war, and lost his right leg. 卡特在战争中受伤残废，失去了右腿。

　　2. unaffected: adj. ① not influenced 不受影响的 ②natural in behavior or character自然的

　　The northwest was unaffected by the drought. 西北部不受干旱的影响。

　　the unaffected delight of a child小孩天真无邪的快乐

　　disaffected: adj. discontented; lacking loyalty (政治上)不满的；叛离的

　　The people are becoming disaffected towards the president. 人们对总统越来越不满。

　　3. disbelief: n. lack of belief不相信；疑惑

　　He listened to my story with an air of growing disbelief. 他听我说这件事，越听越显示出疑惑的样子。

　　4. uninterested: adj. not interested不感兴趣的

　　Bob seems uninterested in learning anything. 鲍勃好像对学什么都不感兴趣。

　　disinterested: adj. ①willing to judge or act fairly, because not influenced by personal advantage公正的；客观的 ② not caring; uninterested 漠不关心的；不感兴趣的(此义可与uninterested互用)

　　His action was not disinterested because he hoped to make money out of the affairs. 因为他希望从这件事中捞取好处，所以他的行为是不公正的。

　　I'm completely disinterested in football. 我对足球一点也不感兴趣。

　　5. dissatisfied: adj. not satisfied, displeased because something is not as good as you had expected不满意的

　　He was dissatisfied at not getting a better salary. 他对不能获得较高薪水而不满。

　　6. unused: adj. ①not having been used 未用过的 ② not accustomed to不习惯的

　　Put away the unused plates and cups. 把未用过的盘子和杯子收起来。

　　She is unused to flying and gets a little anxious in planes. 她不习惯乘飞机，在飞机上有点慌张。

　　disused: adj. no longer used停用的

　　a disused mine一座停用的矿山

　　以下两组词的前缀in-不是表示否定，而是表示"加强，使，赋予"的意思，等于en-, 大概是为了避免产生歧义，现多用后者en-。

　　7. inclose = enclose: v. to surround sth., esp. with a fence or wall围绕

　　You'd better enclose the garden with a higher wall. 你最好用高一点的墙围住庭院。

　　disclose: v. to make known; to show by uncovering透露；揭露

　　The police disclosed that the man had been a spy. 警方揭露这名男子曾经是个间谍。

　　8. intrust = entrust: v. to give (someone) the charge of (something) with complete trust 委托

　　I entrusted my estate to him. 我将财产委托他代管。

　　distrust: v. & n. have no belief in; (to) lack of trust 不信任；疑惑

　　He's so suspicious he would distrust his own mother. 他这人疑心太重，连自己的母亲也不相信。

　　He keeps his money at home because he has a great distrust of banks. 因为他不相信银行，所以就把钱存放在家里。

　　Fill in the blank with a word, according to the meaning taken in the brackets.

　　1. An accident________him from playing football. (was unable, disabled)

　　2. Capes had the gift of easy, ________writing, coupled with very clear and logical thinking. (unaffected, disaffected)

　　3. His________kindness to us in our days of misfortune can never be forgotten. (uninterested, disinterested)

　　4. The children are________to city life. (unused, disused)

　　5. Most of the people interviewed requested that their identity should not be________. (enclosed, disclosed)

　　6. All employees________with the care of children are checked by the police. (entrusted, distrusted)

　　参考答案: 1. disabled 2. unaffected 3. disinterested 4. unused 5. disclosed 6. entrusted

　　(文/祖 林; 英语通大学英语六级考试版2004年第7期;版权归英语辅导报社所有，独家网络合作伙伴新浪教育，未经许可，不得以任何形式进行转载。)