系动词和助动词区别 用法

如题所述

第1个回答  2016-08-13
1、系动词本身有词义,但不能单独用作谓语,其后要跟形容词或名词等作表语,即系表结构(系动词与表语一起作谓语)。常见的系动词有:be , feel, smell, sound, taste,look ,get, turn , keep ,stay 等。
2、助动词本身没有意义,其与其它动词一起构成某种时态、语态、疑问句和否定句。
如:
1). He is/ feels / looks happy . (is/ feel / look 是系动词)
2). The dish smells / tastes delicious .(smell / taste 是系动词)
3). Keep calm . ( keep 是系动词)
4). The leaves turn green in spring .( turn 是系动词)
5). He is doing his homework now. (助动词is 与doing 构成现在进行时态)
6).They didn't go to the park yesterday . (助动词didn't 构成否定句。)
7). He has been to Beijing . (助动词has 与动词过去分词构成现在完成时态)
8). He won't come back until next week . (助动词 won't 后跟动词原形构成一般将来时态)
9). Do you often get up at six in the morning ?(助动词do用于句子开头构成一般疑问句。)
10). The bridge was built last month . ( 助动词was 与动词的过去分词构成被动语态。)