指示代词：标识人或事物的代词，用来代替前面已经提到过的名词。
this ,these ,that ,those
例句：
This is his book.
Those apples were his. (were be 的过去时复数)
不定代词：指代不确定的人或者事物。
one,the other,some ,any,something,onthing.
例句
No one knows where he is.
Some of the boys want to go to Shanghai,but the others want to go to Xi’an.
Each of the students has got a book.
练习
these teachers are from China.
I know nothing about this person.
I have something to tell you.
形容词
名词 通常指代事物或人，可以是具体的可以是抽象的。形容词是形容和修饰名词的成分
形容词通常形容人或者事物的状态，性质，大小等，通常用在名词前，be动词后面。
beautiful就是一个形容词
the beautiful girl 形容词在名词前面
the girl is beautiful 形容词在be动词后面
The + 形容词 = 复数名词，表示一类.后面的动词使用复数。
old —> the old
young—>the young
The old need more care than the young.
练习
She is a good student.
The bike is expensive.
The rich sometimes complain their empty life
