英语中的人称代词(Personal Pronouns)有主格、宾格和所有格之 分，如：

I, me, my ; he, him, his ; they, them,their等。

顾名思义，主格(The nominative case)用作主语，宾格(The objective case)用作宾语，所有格(The possessive case)则表示所有之物。

在实际运用中，主格和宾格代词有时会混淆。下面是常见的问题：

⒈在复合结构里，人称代词的主格和宾格在单独使用时，没有问题，如很少人会犯下这样的错误：

(1)Wilcox spoke to I.

(2)Her knew what had happened.

但在复合结构中，错误就难免了，如：

(3)Wilcox spoke to my friend and I.

(4)He and her knew what had happened.

(5)This is between you and he.

这种错误是可避免的。第一，在有介词的复合结构中，特别要注意，第二个人称代词，必须用宾语，如："for you and me"和 "between Maria and him".第二，试把复合结构中的另一部分暂时用括号围起来，那么该用的格就容易辨别了，如：

(6)This message is for (My father and) I or me.

(7)(Marry and) he or him went downtown together.

显然的，(5)里的代词是宾格的"me", (6)里的代词是主格的"he".

⒉在比较结构里，连接词"as"或"than"后面，按理用主格式，但在口语中，人们常用宾格形式，学美式英语者，更是如此：

(8)a. You did as well as she.

b. You did as well as her.

(9)a. I am older than he.

b. I am older than him.

(a)和(b)两种说法，都可接受。但如果"as"和"than"后头分句的主语和词动都要完整出现的话，这时的人称代词，就必须是主格，如下：

(10)You did as well as she did.

(11)I am older than he is .

此外，还有一点要注意，就是"as"和"than"后面虽然在语法上用主格好，用宾格也可，但是有时意思会有所不同。试比较(a)和(b)：

(12)a. Jason praised Maria more highly than I.

b. Jason praised Maria more highly than me.

(12)a和b都被接受，但(12)a等于(13)a，而(12)b等于(13)B：

(13)a. Jason praised Maria more highly than I did (= I praised Maria).

b. Jason praised Maria more highly than he praised me.

显然，这两句的深层意思大有差别。遇到这种情形，为了避免误解，不妨根据要表达的意思用完整的句式表达出来。换句话说，必要的话，要用(13)这句子。

不然，把(13)a变成(14), (13)b变成(15)也可：

(14)I did not praise Maria as highly as Jason did.

(15)Jason did not praise me as highly as he praised Maria.