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。