系动词亦称连系动词（Link Verb），作为系动词，它本身有词义，但不能单独用作谓语，后边必须跟表语（亦称补语），构成系表结构说明主语的状况、性质、特征等情况。系动词后不可接副词，接的是形容词。大致分六种：
1. 状态系动词
用来表示主语状态，只有be一词，例如：
He is a teacher. 他是一名教师。（is与补足语一起说明主语的身份。）
I am fine.
The earth is as round as a ball. 地球像球一样圆
2. 持续系动词
用来表示主语继续或保持一种状况或态度，主要有keep, rest, remain, stay, lie, stand,
He always kept silent at meeting. 他开会时总保持沉默。
This matter rests a mystery. 此事仍是一个谜。
Andersen remained single all his life
After his election to a high office, he remained modest. 在被选为高级领导干部之后他仍然谦虚。
The weather has stayed hot recently. 最近天气一直很热。
The shop stays open till seven o'clock. 那家商店一直营业到7点
What I ate lies heavy on my stomach. 我吃下的东西滞留在胃里。
The door stood open. 门开着。
3. 表像系动词
用来表示"看起来像"这一概念，主要有seem, appear, look, “看起来、显得”seem/ appear+(to be ) adj/ n
He seems (to be) very sad. 他看起来很伤心。
She seemed （to be ） an honest woman. 她看上去是个老实人。
He seemed ( to be ) interested in the book.
She seems (to be) a bit nervous.
It appears (to be )a true story. 这似乎是个真实的故事。
He appeared (to be) discouraged.
He looks tired. 他看起来很累。
He looked(看起来) angry/ sad/ happy.
He looked（看着）angrily/ sadly/ happily at me. (look 实意动词)
The soup looked, smelt and tasted good
4. 感官系动词
感官系动词主要有feel, smell, sound, taste、look (注意：此时不能用被动语态)
Ice always feels cold to us. 对我们来说冰摸起来总是冷的。
The box feels strong. 这箱子摸起来很结实
This flower smells very sweet. 这朵花闻起来很香。
Her idea sounded great. 她的主意听起来很不错。
The newly-invented soft drinking tastes quite unique.
He doesn't look well (adj. )
5. 变化系动词
这些系动词表示主语变成什么样，变化系动词主要有become, grow,get, turn, come, run. go,fall（asleep）
He became mad after that. 自那之后，他疯了。
She grew rich within a short time. 她没多长时间就富了。
The fox may grow grey, but never good. 狐狸会变老，但不会变好。（谚语）
It was growing dark. 天色渐渐暗下来。
The weather gets warmer and the days get longer in spring. 春天天气越来越暖和，白天越来越长。
She got angry with her son.
He turned doctor in 1980. (doctor前不用冠词)
Twenty years later, he turned teacher. (teacher前不用冠词)
Everything will come all right in the end. 最终一切都会变好的
Nothing goes wrong
Eggs can go bad easily in summer. 夏季，鸡蛋容易变坏
His horse fell lame.他的马瘸了。
He has suddenly fallen ill.
The child fell asleep while he was doing his homework. 孩子在做作业时睡着了
6. 终止系动词
表示主语已终止动作，主要有prove, turn out, 表达"证实"，"变成"之意 (注意, 此时不能用被动语态。)sth prove (to be)+adj./n
The rumor proved false. 这谣言证实有假。
The search proved difficult. 搜查证实很难。
His plan turned out a success. 他的计划终于成功了。（turn out表终止性结果）
Things worked out quite well . 事情的结坚果很不错。
Einstein's theory proved (to be) right. 爱因斯坦的相对论被证实是正确的。
Her words proved (to be) true.
