1)指示代詞分單數(this / that)和復數(these / those)兩種形式，既可作限定詞又可做代詞，例如：

單數 復數

限定詞：This girl is Mary.Those men are my teachers.

代 詞：This is Mary. Those are my teachers.

2)指示代詞的句法功能

指示代詞主要有四個，即this, that, these 和 those。它們在句中可作主語、賓語、表語、定語等。

This is my book.(主語)

I want that.(賓語)

My book is that.(表語)

I like that dress.(定語)

注意：

1. 為避免重復，可用 that 和 those 代替前面提到的名詞。如：

The playground of this school is bigger than that of that school. (That=the playground)

My seat is next to that of the mayor.(that=mayor’s seat) 我的座位在市長座位旁邊。

2. 用來回指上文提到的事情時，可用this 或 that，但是若要指下文敘述的事情，通常要用 this。如：

--She is a beautiful girl.

--Who said that?

I want to know this: Is she beautiful? 我想知道這一點：她美嗎?

3. 在打電話時，通常用 this 指自己，用that指對方：

Hello. This is Jim. Is that John? 喂，我是吉姆，你是約翰嗎?

4. 除用作代詞外，this 和that 還可用作副詞，用以修飾形容詞或副詞，意為"這么"、"那么"，相當于 so。

如：

I’ve done only that much. 我所做的就這么多。

Is he always this busy? 他總這么忙嗎?

5. 指示代詞this, that 和these在作主語時可指物也可指人，但作其他句子成分時只能指物，不能指人。而those作賓語后接定語從句時可以指人。而且只有that、those后面可以跟定語從句。

如：(對)That is my teacher.那是我的老師。(that作主語，指人)

(對)He is going to marry this girl.他要和這個姑娘結婚。(this作限定詞)

(錯)He is going to marry this.(this作賓語時不能指人)

(對)I bought this.我買這個。(this指物，可作賓語)

He admired those who looked beautiful. 他贊賞那些外表漂亮的人。(those指人)

(錯) He admired that who danced well.(that作賓語時不能指人)

(對)He admired that which looked beautiful.他贊賞外表漂亮的東西。