［误］There are two As in this word.
［正］There are two A's in this word.
［析］在大写字母缩写形式的复数表达法中应加s，但如字母是A、I时，为了防止与As和Is相混，则要用's即A's，I's
［误］There are three 6s and two 3s in my telephone number.
［正］There are three 6's and two 3's in my telephone number.
［析］在小写字母与数字的复数形式表达法中要用's
［误］We have many woman teachers in our school.
［正］We have many women teachers in our school.
［析］一般组合名词变为复数形式时只将词中心词变为复数如：?
half brother—half brothers(同父异母或同母异父的兄弟)daughter in law—daughtersin law,(儿媳)但要注意的是：man driver—men drivers(男司机) woman doctor—women doctors(女大夫)grown up—grown ups(成年人) 但是boy student—则变为boy students
［误］Physics are very difficult to learn.
［正］Physics is very difficult to learn.
［析］虽以s结尾但只能用作单数名词有：科学，学科名字：Physics. Mathematics politics游戏名称：bowls 专有名称：Niagara Falls(尼亚加拉瀑布)  其他名词：news(消息，新闻)
［误］There is a people in the room.
［正］There is a person in the room.
［正］There is a man in the room.
［析］people是复数名词，不可用作单数，如要用来讲一个人时应用a person, a man, a woman。同样的词有police.要讲一个警察时则要用a policeman, a policewoman。
［误］Where is my shoe?
［正］Where are my shoes?
［析］常常只用作复数形式的词有trousers, pants, shorts(短裤)，socks(袜子),shoes, gloves(手套)。但如果只找其中的一个则要指明，这时还是应用单数形式。如：Where's my left glove?(我左手的手套在哪?)
［误］I paid five pennies for the sweet.
［正］I paid five pence for the sweet.
［析］英语中便士有两个复数形式pence用来表达一定数量的钱。而pennies是指一个个的硬币，如：I want to change this note for pennies.我想把这纸币换成硬币。(即一便士一个的硬币)。
［误］There are many fruit in the shop.
［正］There are many fruits in the shop.
［析］物质名词为不可数名词，但是用来表示种类时则可以用作可数名词，这里应译为各种各样的水果。?
［误］There is a new car. It is Jone's and Mary's.
［正］There is a new car. It is Jone and Mary's.
［析］有生命名词的所有格，如果是单数名词则加's如：Mary's car.如果是以s结尾的复数名词则只在s后面加’如：teachers' offices.如果是复数名词但不是以s结尾，则只加’s，如：children's palace 组合名词的所有格是在最后一个词尾加's如：girl friend —girl friend's someone else—someone else's a week or three—a week or three's如名词后有同位语时，则应加在同位语的词尾上，如：It is my girl friend, Mary's car.要注意的是当两个名词并列时，如表示归两人共同所有，则在最后一个名词后面加's，如果表示分别所有则在两个名词后分别加's，如：This is Mary and Jone's home.即Mary与Jone是一家人。这是他们共同的家。而These are Mary's and Jone's homes.则应译为这里是Mary的家与Jone 的家。
［误］It is really beautiful. It is a work of nature.
［正］It is really beautiful. It is a Nature's work.
［析］无生命名词的所有格应用of结构。但是's形式的所有格可用于以下无生命的名词：表示时间的词：today's newspaper, a twenty minutes' walk, an hour's, rest 表示长度的词：three metres' distance, a boat's length， twenty miles' journey 表示重量的名词：two pounds' weight价格名词：two dollars'worth拟人化的名词：Nature's work, nature's  lesson(大自然的教训)及国家、机关、团体、城市等机构性名词：the university's library
［误］He is an old friend of my father.
［正］He is an old friend of my father's.
［析］这是英语中的一种习惯用法而不要根据语法去推理。如：This pen is Tom's.
［误］My father is a good cooker.
［正］My father is a good cook.
［析］一般动词加上er后则转意为执行该动作的执行者，如:teach(教)—teacher(老师),think(想)—thinker(思想家),drive(开车)—driver(司机),sell(卖)—seller(卖物者)……但不能总是以此类推，比如cook是动词“做饭”。而cook也可作为名词“厨师”讲，而cooker则为厨具，餐具，即锅、碗、勺等做饭用具。