1)、定義：人稱代詞是用來(lái)指代人、動(dòng)物或事物的代詞。它必須在人稱(第一人稱、第二人稱、及第三人稱)、數(shù)（單數(shù)、復(fù)數(shù)）以及性（陰性、陽(yáng)性、中性）三方面與被指代的名詞一致。
如：I am a student.
Tom is a boy, and he is a student.
Mary is very pretty, and she likes singing.
The boys are students, and they are in the room.
The doy is small. It is Tom's.
2、人稱代詞的句法功能
A) 人稱代詞有主格和賓語(yǔ)之分：主格用作主語(yǔ)，賓格用作賓語(yǔ)。
B) 人稱代詞的主格形式在在句中作主語(yǔ)和表語(yǔ)。
如: I like music(主語(yǔ)).
She is a teacher.(主語(yǔ))
She and I are good friends(主語(yǔ)).
Neither she nor I am student.
——I saw the boys this morning.
——Are you sure it was they(表語(yǔ))?
C) 人稱代詞的賓格在句子作動(dòng)詞的賓語(yǔ)，或者介詞的賓語(yǔ)。
如：I saw him at the party(賓語(yǔ)).
I haven't seen them recently. (賓語(yǔ))
I bought a book for them. (作介詞賓語(yǔ))
=I bought them a book. (間接賓語(yǔ))
【注意】
a. 在口語(yǔ)中，人稱代詞的主格形式作表語(yǔ)時(shí)，常常可以用賓格替換。
如：It can't be he/him.
——Is this Mr. Green?
——Yes, this is he/him.
b. 在口語(yǔ)中，當(dāng)人稱代詞用于than, as 之后或用于強(qiáng)調(diào)句中被強(qiáng)調(diào)時(shí)，用主格(較正式)和賓格(較口語(yǔ)化)均可以。
如：
He sings better than I/me. 他比我唱得好。
You know more than she/her.
She is as tall as me(I am).
c. 單獨(dú)使用的人稱代詞通常用賓格，即使它充當(dāng)?shù)氖侵髡Z(yǔ)也是如此。如：
“I like English.”
“我喜歡英語(yǔ)�！�
“Me too=I like English too.”
“我也喜歡�！�