半助动词是什么

半助动词是什么

问题一：半助动词是什么啊，举个例子 The boy has to make a living by begging.
男孩不得不通过乞讨维持生计。
He is unwilling to help me with my English.
他不愿帮我学习英语。
Every clause is obliged to obtain a finite verb.
每个句子必须包括一个限定动词。
We were about to start when it rained.
下雨时，我们即将出发。
He seems to be very disappointed.
他好像非常失望。
I don’t have to buy a new house.
我不必买新房子。
He didn’t seem to feel in love with her.
他好像没有爱上她。问题二：英语中的半助动词和汉语中的半助动词有何区别 e what have only one life问题三：主动词的半助动词和主动词 半助动词在功能上介于主动词和助动词之间，本身有词汇意义，可分为三类：a.以be为中心成分，如：be about to　 be going tobe bound to 　be able tobe due to　 be sure tob.以have为中心成分，如：had better/best　 have got tohave toc.以seem等为中心成分，如：seem to 　 turn out to beappear to 　 fail tohappen to 　 tend to2.半助动词既可是限定形式（体现时态，语态特征），也可是非限定形式（不定式或现在分词）。半助动词后的主动词都用带to 的不定式，这种不定式可以是一般形式、进行式或完成式，如：He appears to have many friends.他似乎有许多朋友。He seems to be enjoying himself at the party.在聚会上，他看起来很快乐。Now，I‘m having to take a bus.现在，我不得不坐公共汽车。You are supposed to have finished your term paper by Sunday evening.在周日晚上，你应该已经做完了你的学期论文

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