Predicate verbs
认识谓语动词
谓语动词是句子的引擎。它决定主语做什么、是什么、处于什么状态，同时承载时态、语态、语气。可以把谓语动词分成两大类：实义动词和非实义动词（系动词）。
有实际动作含义，独立做谓语
及物动词
后面必须接宾语
不及物动词
动作本身完整
连接主语和表语，说明主语的状态
be 动词
am / is / are / was / were
感官动词
look / sound / smell / taste / feel
变化系动词
become / get / turn / grow
表象系动词
seem / appear / look
持续系动词
keep / remain / stay
终止系动词
prove / turn out
实义动词
Transitive Verb
及物动词
后面必须接宾语，动作作用到某个对象上。
I love you.
She reads books.
He bought a car.
及物动词的宾语不能省略。
Intransitive Verb
不及物动词
动作本身已经完整，不需要宾语。
Birds fly.
He runs every morning.
She laughed.
不及物动词后面不能直接接宾语（除非加介词）。
非实义动词（系动词）
Be Verb
be 动词
最基础的系动词，表示主语是什么、在哪里。
I am a student.
She is in the room.
They were happy.
am/is/are 现在式，was/were 过去式。
Sense Verb
感官动词
通过感官感受到的状态。
The food smells good.
You look tired.
This feels soft.
感官系动词后面接形容词，不要用副词。
Change Verb
变化系动词
表示主语从一个状态变成另一个状态。
She became a doctor.
It is getting dark.
The leaves turned yellow.
become / get / turn / grow 表示状态变化。
Appearance Verb
表象系动词
表示主语看起来、似乎是什么样。
He seems happy.
She appears confident.
The plan looks good.
seem、appear 常表推测语气。
Continuity Verb
持续系动词
表示主语持续保持某个状态。
Keep quiet.
He remains silent.
She stayed calm.
keep / remain / stay 强调状态不改变。
Result Verb
终止系动词
表示主语最终被证明是什么样。
He proved innocent.
The rumor turned out false.
prove / turn out 表示经过验证后的结果。