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.