表示人、事物的形状、性质或者动作、行为等的状态的词叫形容词。形容词的否定式是在形容词前用否定副词"不"。
Words that describe the shape or property of a person or thing, or the state of a movement or action, are called adjectives. The negative adverb 不 is placed before an adjective for the negative form.

一. 形容词有以下几类：
    Adjectives include the following kinds:

表示人或事物的形状的：
Describing shape: 大 小 高 矮 红 绿 齐  美丽

表示人或事物的性质的：
Describing property or quality: 好 坏 冷 热 对 错 正确 伟大 优秀 严重

表示动作或行为等的状态的：
Describing the state of a movement or action: 快 慢 紧张 流利 认真 熟练  残酷

二. 形容词的用途：
    Functions:

作定语： As an attributive:
形容词最主要的用途是修饰中心语。例如：
Adjectives are mainly used as modifying attributive. For example: 红裙子 a red skirt
绿帽子  a green cap
宽广的原野 vast expense of open country
明媚的阳光 bright sunshine

作谓语： As the predicate:
时间紧迫。  Someone is being pressed for time.
她很漂亮。  She is very beautiful.
茉莉花很香。  Jasmine is very fragrant.
他很高。  He is very tall.

作状语： As an adverbial adjunct:
形容词的一个重要用途是在动词前作状语。例如：
One of the important uses of adjectives is to be put before a verb as an adverbial adjunct. For example: 快走。  Hurry!
他多喝了点儿。  He had a drop too much.
你应该正确地对待批评。 You should take a correct attitude towards criticism.
同学们认真地听讲。  Students listen to the teacher attentively.

作补语： As the complement:
形容词常作谓语动词的补语。例如：
Adjectives often serve as complements to predicate verbs. For example: 先在纸上画图形，再选好树叶. First, drew a pattern on a piece of paper and selected some leaves.
把你自己的衣服洗干净。 Clean your clothes.
雨水打湿了她的头发。 The rainwater wet her hair.
风吹干了衣服。。 The wind dried the clothes.

作主语： As the subject:
谦虚是中国传统的美德。 Modest is a traditional virtue of China.
骄傲使人落后。 Proud will make you drop behind.

作宾语： As the object:
女孩子爱漂亮。  Girls love being pretty.
他喜欢安静。 He likes quietness.