小博士：细心的同学们肯定发现了有些名词有单数(singular)和复数(plural)两种形式，而有些名词只有单数形式，这是怎么回事呢？让我来告诉你吧。英语中，名词按其所表示的事物的性质，可分为可数名词(countable noun)和不可数名词(uncountable noun)，可数名词有复数形式，不可数名词一般没有复数形式。名词单数变复数的变化规则见下表。

比一比，看谁写的单词多！

1　　直接加-s的单词有：________________________________.

2　　加-es的单词有：___________________________________.

3　　变y为i再加-es的单词有：__________________________.

4　　不规则变化的单词有：_______________________________.

句型转换（5%）
【小题1】These are my grandparents. (变一般疑问句)
_______ these ______ grandparents?
【小题2】Is this his picture? (作肯定回答)
_______, ______ is.
【小题3】The tape player is in the room. (对划线部分提问)
_______ ________ the tape player?
【小题4】She is a nice girl. (单数变复数)
_______ are nice ______.
【小题5】They are erasers. (复数变单数)
______ is _____ eraser.

句型转换（5%）

1.These are my grandparents. (变一般疑问句)

_______ these ______ grandparents?

2.Is this his picture? (作肯定回答)

_______, ______ is.

3.The tape player is in the room. (对划线部分提问)

_______ ________ the tape player?

4.She is a nice girl. (单数变复数)

_______ are nice ______.

5.They are erasers. (复数变单数)

______ is _____ eraser.