名词的所有格，表示的是两个名词的的所有关系，也就是"***的***"。

++++++++++++++++++++++++++++++++++++++++++++++++

（1）基本上都是直接加's
          Helen's book, Mary's pocket; the old man's boat
（2）复数名词
      1. 如果复数名词以s结尾，则只加'
            Teachers' Day, the students' lab, girls' game
      2. 如果复数名词不以s结尾，仍加"'s"
　　   Children's Day, Women's Day, men's talk
（3）表示共有（见notes1）时，名词的所有格应加在后面那个名词上
           Tom and Jack's father, Harry and George's room
（4）动物或者无生命事物的名词所有格一般不是在词尾加's，而
       1. 用of表示：
             the call of nature, a map of Shanghai, the floor of the bathroom
       2. 用to表示：
             the key to the door, the way to India

++++++++++++++++++++++++++++++++++++++++++++++++

练习：
1. Parents should listen to what ___ have to say.
A. Children   B. Children’   C. Childrens’   D. Children’s
解答：和今天所学内容无关, 纯属烟雾弹, 选A。
2. September 10th is ___ Day.
A. the Teacher   B. Teachers’   C. Teacher   D. Teacher’s
解答：D, 考察有没有仔细看例子。
6.    The two desks here are ___. You may use the desk over there.
A. Mary and Jane   B. Marys and Janes  C. Mary and Jane’s
D. Mary’s and Jane’s
解答：这是两个人共有的还是分别的东西？由desks可以判断是分别的，所以选D（见notes1）。

++++++++++++++++++++++++++++++++++++++++++++++++

notes:
1. 关于Tom and Jack's father, Harry and George's room等所有格， 表示的是"共有"，也就是说Tom和Jack共有一个父亲；而Harry和George分享同一间屋子。但凡要表示"分别(各自)的..."，则应该一一列出，即Tom's and Jack's fathers; Harry's room and George's room....
2. 文中第（4）大点中有用of表示和to表示的区别，虽是习惯用法所致，但也有些规律可循。of一般表示“属性”，而to则表示“动作、行为的趋向”。也就是说和of、to这两个介词本身的习惯表达相关联。