退休养老金上调最新消息:onebooks twoboxes 为什么有"s"有"es"呢？有什么区别？

1)单数名词加s: students, apples, bags, trees, books, brothers.?
2)以s、x、sh、ch结尾的名词加es: glasses, boxes, brushes, matches.?
3)以辅音字母加y结尾的名词，变y为i加es: cities, babies, enemies.?4)以f或fe结尾的名词，多数变f为v加es: wives, knives.但有些词只加s: roofs, proof s, chiefs.?
5)以o结尾的名词，有些加es: Negroes, heroes, tomatoes, potatoes.其它加s: radio s, zoos, pianos, photos.
? 6)不规则名词：foot→feet, goose→geese, tooth→teeth, child→children, man→me n, woman→women, sheep→sheep, deer→deer, mouse→mice.
7)某些外来词变复数：datum→data, medium→media, bacterium→bacteria, curriculum→curricula, criterion→criteria, phenomenon→phenomena. (?um/?on→a)?analysis→analyses, basis→bases, crisis→crises, diagnosis→diagnoses.(?is→es )
? 8)复合名词变复数：以不可数名词结尾的复合名词无复数形式，如：homework.?
以man或woman为前缀的复合名词变复数，前后两个名词都变复数，如：manservant→menservants, woman student women students.?
其它复合名词变复数：grown?up→grown?ups, brother?in?law→brothers?in?law, stand?by→stands?by.?
9)复合形容词做定语时，其中的名词保持单数：a six?year?old boy，a two?hundred?page book
【例句】?A second doctor must confirm that these criteria ______ and the death must be re ported to the police department.?
A) has been met
B) have been met?
C) was met
D) was being met?
criteria是复数形式，故A，C，D都为错误选项。正确答案为B。
1) The university authorities are seriously considering abandoning the traditional______class.?
A) fifth minutes
B) fifty?minutes?
C) fifty?minute
D) fifty minute's?
复合形容词用作定语时，其中的名词不变复数，故B不对。A不能做定语，D应为fifty minutes'，正确答案为C。

可数名词与不可数名词的相互转化
可数名词与不可数名词在一定条件下可以转化。很多表示蔬菜、动物等的名词，一般来说是可数的，但是表示餐桌上的食品时，就转换为不可数名词。?
【例如】?There are some chickens in the yard.(院子里有几只鸡。)?Would you like chicken or fish?(你喜欢吃鸡，还是吃鱼?)?
物质名词或抽象名词一般是不可数的，但用来表示若干类和数量之多时，可转化为可数名词，但往往意义有所变化，如：water(水)→waters(水域)，sea(海)→seas(海域)?
【再如】?
Beer is a kind of nice drink in hot summer.?
I had two beers and a big bowl of beef.?
当抽象名词表示“某一种”或“某一方面”的抽象概念时，其前可加a/an.?【例如】?
What he did showed a certain honesty which made me admire him.