be动词怎么用?

有时候写句子主语后面都会烦恼到底要不要用到be动词,求解请举例。谢谢

be是一个多功能动词,在初级英语里可见四种用法:
  功能一,系动词be  be为连系动词,中心词义是"是",句型为"主+系+表"结构。be的形式常用am, is, are(现在式);was, were(过去式);will/can/may/must be(助动词/情态动词+原形);have/has/had been(助动词+过去分词)等。如:   To help animals is helping people.(一般现在时)  The twins were very busy yesterday.(一般过去时)  It will be sunny tomorrow.(一般将来时)  She has been ill for over a week.(现在完成时)  功能二,助动词be  助动词be,无词义,辅助主要动词一起在句中作谓语动词。用法如下:  1. be+doing:构成进行时态,有现在和过去两种进行时态。如:  The girls is reading and copying the new words now.  Young Tom was always asking questions and trying out new ideas.  2. be+done:构成被动语态(主语是动作的承受者,done必须是及物动词)。如:  Tea is grown in my hometown.(一般现在时的被动语态)  This building was built three years ago.(一般过去时的被动语态)  Our classroom has been cleaned and tidied already.(现在完成时的被动语态)  How could this kind of cakes be made in your home?(含情态动词的被动语态)  That is a day never to be forgotten.(动词不定式的被动语态)  3. be+going to do,表示"打算或将要做某事",be有现在和过去两种形式。如:  We are going to plant trees in the park.  I didn't know if she was going to come here.  4. be+to do,表示"按计划安排将要做某事"。如:  The new shop is not to be opened till next Monday.   One night an angel came to Mary and told her that she was to have this special boy.  功能三,there be  there be句式为:there be+主语部分+状语部分,表示"某处存在某物",be常用现在时,过去时和将来时等。如:  Oh, cool! And there are many things to see. There is even a deer park in Sanya.  There are about 80 pyramids in Egypt.   Will there be a football match in your school next week?   功能四,实义be  可以将be视为实义动词,因为它具有实际的词义,如"成为;做;发生;举行;逗留;到达"等。如:  His daughter wants to be a doctor for animals in her twenties.  Kate's birthday party will be at half past six this evening.  Jim has been in China for more than two years, but he has not yet
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第1个回答  2013-10-19
be是一个连系动词,它有自己不同的形式
现在时:be 进行时:being 过去时:was/were 过去分词:been
它的后面必须跟形容词或名词作表语,与之构成系表结构,充当句子的谓语。
i am a student主语:i 谓语:am a student(系表结构)
being是它的现在进行时态,一般不单独用,而是用于现在进行时的被动语态。(being+动词过去分词)
the bike is being repaired.单车正在被修理中。
it is being finished by him这正在被他完成中。
been是它的过去分词,也不一般单独使用,而是用于现在完成时、过去完成时以及需要它的句子。
i have been here for a long time.我已经到这里有一段时间了。
至于你的问题,这与你想表达的意思有关。
你的工作是什么?
what do you do? what is your job?
那么这里选用do和is有什么根据呢? http://www.qnr.cn/waiyu/
第一句里面,第二个do是指你做什么,也就是你的工作,就是一个实义动词。按中文说,what you do已经足够了。可是英语里面就不行,必须跟一个助动词,也就是do.
这里就有了一个结论:当句子中有动词时,我们就用助动词do或是does.如果没有动词时,我们就选用is或是are,也就是be
第2个回答  2019-12-11
第3个回答  2020-01-10
第4个回答  2013-10-19
当句子中有两个动词时,不用be动词(看情况,是否可以填be动词)
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