系动词系动词,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(形容词),构成系表结构说明主语的状况、性质、特征等情况
英语除动词be 之外,还有一些动词也可以做系动词,如表示状态或情况的:keep, look, feel, appear, lie, remain, seem, stay, smell, sound, taste 等;以及表示变化的: get, grow, turn, fall, run, become, go, 等
to be 可以加在 seem, prove, remain, appear 等系动词和其后的名词或形容词之间,但也可以省略
The task proved (to be) impossible
They seem (to be) such friendly people, but they never replied to our invitation
注意:在 seem, appear 等词后,可加其他非to be 不定式,但这时他们不是系动词,而是不及物动词
Courtesy, politeness, good manner
Call it what you will, the supply never seems to equal the demand
非人称代词it 做句子的形式主语1
代表不定式 E
It is absurd to be afraid under such circumstances
代表动名词E
It is terrible trying to keep up with the Jones
代表 that 引导的从句E
It is plain to everyone that she wa