为什么是andi而不是andme

and是并列关系的连词，所以and连接的前后两个词是通常是词性相同，意义相近或相对的。

所以，and前面的词是主格则后面是and I，and前面的词是宾格则后面是宾格，即and me。

例：My mother and I are going to visit my grandfather  tomorrow.

My teacher praised Tom and me for our homework today.

英语中以下以做主语

1）名词

2）代词（英语中能做主语的代词有:）

人称代词主格：I ，he，she，we，they，you，it.

指示代词：this，that，those，these

不定代词：one，each，some，any，something，everything，nothing，anything

关系代词：which，that，who

3）不定式如：To do morning exercises is good for our health.

4）动名词如：Seeing is believing.

5）数词作主语，如：Two will be enough.两个就够了。

6）名词化的形容词作主语，如：The blind and the lame are well cared for in our country.

7）短语作主语，如：How to do well is an important question.

8）主语从句，如：That the earth goes/moves aroud the sun is truth.