1)have +过去分词,构成完成时态,例如: He has left for London. 他已去了伦敦。 By the end of last month, they had finished half of their ... [查看全文]
1) be +现在分词,构成进行时态,例如: They are having a meeting. 他们正在开会。 English is becoming more and more important. 英语现在越来越重要。 2... [查看全文]
1)协助主要动词构成谓语动词词组的词叫助动词(Auxiliary Verb)。被协助的动词称作主要动词(Main Verb)。 助动词自身没有词义,不可单独使用,例如: He doesn't... [查看全文]
系动词亦称联系动词(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。 说明: ... [查看全文]