1. clothes, cloth, clothing

　　clothes 统指各种衣服，谓语动词永远是复数；cloth 指布，为不可数名词；clothing 服装的总称，指一件衣服用a piece of, an article of .

　　2. incident, accident

　　incident 指小事件，accident 指不幸的事故。如：He was killed in the accident.

　　3. amount, number

　　amount 后接不可数名词， number 后接可数名词，如：a number of students.

　　4. family, house, home

　　home 指家，包括住处和家人，house 指房子、住宅，family 指家庭成员，如：My family is a happy one.

　　5. sound, voice, noise

　　sound 指自然界各种各样的声音，voice 指人的嗓音，noise 指噪音，如：I hate the loud noise outside.

　　6. photo, picture, drawing

　　photo 指用照相机拍摄的照片，picture 可指相片、图片、电影片，drawing 指画的画，如：Let's go and see a good picture.

　　7. vocabulary, word

　　vocabulary 指词汇，一个人拥有的单词量；word 指具体的单词。如：He has a large vocabulary.

　　8. population, people

　　population 指人口、人数，people 指具体的人，如：China has a large population.

　　9. weather, climate

　　weather 指一天内具体的天气状况，climate 指长期的气候状况，如：The climate here is not good for you.

　　10. road, street, path, way

　　road 指具体的公路、马路，street 指街道，path 指小路、小径，way 指道路、途径。如：take this road; in the street; show me the way to the museum.

　　11. course, subject

　　course 指课程（可包括多门科目），subject 指科目（具体的学科），如：a summer course.

　　12. custom, habit

　　custom 指传统风俗、习俗，也可指生活习惯，后接to do；habit 指生活习惯，习惯成自然，后接of doing. 如：I've got the habit of drinking a lot.

　　13. cause, reason

　　cause 指造成某一事实或现象的直接原因，后接 of sth./doing sth.；reason用来解释某种现象或结果的理由，后接for sth./doing sth.， 如：the reason for being late.

　　14. exercise, exercises, practice

　　exercise 指运动、锻炼（不可数），exercises 指练习（可数），practice 指（反复做的）练习。如：Practice makes perfect.

　　15. class, lesson

　　作“课”解时，两者可以替换；指课文用lesson，指班级或全体学生用class，如：lesson 6; class 5.

　　16. speech, talk, lecture

　　speech 指在公共场所所做的经过准备的较正式的演说，talk 指日常生活中的一般的谈话、讲话，lecture 指学术性的演讲、讲课，如：a series of lecture on…

　　17. officer, official

　　officer 指部队的军官，official 指政府官员，如：an army officer .

　　18. work, job

　　二者均指工作，work 不可数，job 可数，如：a good job.

　　19. couple, pair

　　couple 主要指人或动物，pair 多指由两部分组成的东西，如：a pair of trousers.

　　20. country, nation, state, land

　　country 侧重指版图、疆域，nation 指人民、国民、民族，state 侧重指政府、政体，land 指国土、国家。如：The whole nation was sad at the news.

　　21. cook, cooker

　　cook 指厨师，cooker 指厨具，如：He is a good cook.

　　22. damage, damages

　　damage 是不可数名词，指损害、损失；damages 为复数形式，指赔偿金，如：$900 damages.

　　23. police, policeman

　　police 是警察的总称，后接复数谓语动词；policeman 指某个具体的警察。如：The police are questioning everyone in the house.

　　24. problem, question

　　problem 常和困难连系，前面的动词常为think about, solve, raise；question 常和疑问连系，多和ask, answer 连用。

　　25. man, a man

　　man 指人类，a man 指一个男人。如：Man will conquer nature.

　　26. chick, chicken

　　二者均可指小鸡，chicken 还可以当鸡肉，如：The chicken is delicious.

　　27. telegram, telegraph

　　当“电报”解时，telegram 指具体的，telegraph 指抽象的，如：a telegram, by telegraph.

　　28. trip, journey, travel, voyage

　　travel 是最常用的，trip 指短期的旅途，journey 指稍长的旅途，voyage 指海上航行，如：a three-day trip.

　　29. sport, game

　　sport 多指户外的游戏或娱乐活动，如打球、游泳、打猎、赛马等；game 指决定胜负的游戏，通常有一套规则。如：His favorite sport is swimming.

　　30. price, prize

　　price 指价格，prize 指奖、奖品、奖金，如：win the first prize The price is high/low.

　　31. a number of, the number of

　　a number of 指“许多”，谓语动词用复数。the number of 指“…的数目”，谓语动词用单数。如：The number of students is increasing.

　　32. in front of, in the front of

　　in front of 指范围外的前面，in the front of 指范围内的前面，如：In the front of the room sits a boy.

　　33. of the day, of a day

　　of the day 指每一天的、当时的、当代的，of a day 指暂时的、不长久的，如：a famous scientist of the day.

　　34. three of us, the three of us

　　three of us 我们（不止三个）中的三个，the three of us 我们三个（就三个人）。如：The three of us――Tom, Jack and I went to the cinema.

　　35. by bus, on the bus

　　by bus 表手段、方式，不用冠词；on the bus 表范围。如：They went there by bus.

　　36. for a moment, for the moment

　　for a moment “片刻、一会儿”，for the moment“暂时、一时”，如：Thinking for a moment, he agreed.

　　37. next year, the next year

　　next year 将来时间状语，the next year 过去将来时间状语，如：He said he would go abroad the next year.

　　38. more than a year, more than one year

　　more than a year“一年多”，more than one year“超过一年”（两年或三年等）

　　39. take advice, take the（one's） advice

　　take advice“征求意见”，take the advice“接受忠告”，如：He refused to take the advice and failed again.

　　40. take air, take the air

　　take air“传播、走漏”，take the air“到户外去、散步”，如：We take the air every day.

　　41. in a word, in words

　　in a word“总之、一句话”， in words“口头上”，如：In a word, you are right.

　　42. in place of, in the place of

　　in place of“代替”，in the place of“在…地方”，如：A new building is built in the place of the old one.

　　43. in secret, in the secret

　　in secret“秘密地、暗自地、偷偷地”，一般用作状语；in the secret 指知道内情、知道秘密，一般用作表语。如：My mother was in the secret from t

　　he beginning.

　　44. a girl, one girl

　　a girl 可泛指所有女孩, one girl 指一个女孩，如：Can one girl carry such a big box?

　　45. take a chair, take the chair

　　take a chair“相当于”，sit down“坐下”，take the chair“开始开会”

　　46. go to sea, by sea, by the sea

　　go to sea“当海员、出航”，by sea“乘船、由海路”， by the sea“在海边”，如：go by sea.

　　47. the doctor and teacher, the doctor and the teacher

　　the doctor and teacher 指一个人，既是医生又是老师；the doctor and the teacher 指两个人，一个医生和一个老师。

　　48. in office, in the office

　　in office“在职的”，in the office“在办公室里”，如：He is in office, not out of office.

　　49. in bed, on the bed

　　in bed“卧在床上”，on the bed“在床上”，如：The book is on the bed. He is ill in bed.

　　50. in charge of, in the charge of

　　in charge of“管理、负责照料”，in the charge of“由……照料”，如：He is in charge of the matter. The matter is in the charge of her.