be動詞的用法口訣
【速記口訣】I用am，you用are，is跟著他(he)、她(she)、它(it);單數(shù)形式用is，復(fù)數(shù)形式全用are。
變疑問，一提二改三問號;變否定，更容易，be后not加上去。
【妙語詮釋】變疑問句時，可分三步進行：第一步是”提“，指的是把句中的be動詞提到主語前面;第二步是”改“，指的是把提到句首的be動詞的首字母改成大寫字母，主語的首字母改成小寫字母(如主語是專有名詞則不改);第三步是”問號“，指的是在句末加上問號。
一，系動詞be
be為連系動詞，中心詞義是"是"，句型為"主+系+表"結(jié)構(gòu)。be的'形式常用am, is, are(現(xiàn)在式);was, were(過去式);will/can/may/must be(助動詞/情態(tài)動詞+原形);have/has/had been(助動詞+過去分詞)等。如：
To help animals is helping people.(一般現(xiàn)在時)
The twins were very busy yesterday.(一般過去時)
It will be sunny tomorrow.(一般將來時)
She has been ill for over a week.(現(xiàn)在完成時)
二，助動詞be
助動詞be，無詞義，輔助主要動詞一起在句中作謂語動詞。用法如下：
1. be+doing：構(gòu)成進行時態(tài)，有現(xiàn)在和過去兩種進行時態(tài)。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：構(gòu)成被動語態(tài)(主語是動作的承受者，done必須是及物動詞)。如：
Tea is grown in my hometown.(一般現(xiàn)在時的被動語態(tài))
This building was built three years ago.(一般過去時的被動語態(tài))
Our classroom has been cleaned and tidied already.(現(xiàn)在完成時的被動語態(tài))
How could this kind of cakes be made in your home?(含情態(tài)動詞的被動語態(tài))
That is a day never to be forgotten.(動詞不定式的被動語態(tài))
3. be+going to do，表示"打算或?qū)⒁瞿呈?quot;，be有現(xiàn)在和過去兩種形式。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"按計劃安排將要做某事"。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.
三，be動詞的用法there be句型
there be句式為：there be+主語部分+狀語部分，表示"某處存在某物"，be常用現(xiàn)在時，過去時和將來時等。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?
四，實義動詞be
可以將be視為實義動詞，因為它具有實際的詞義，如"成為;做;發(fā)生;舉行;逗留;到達"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 been to Yichang.
以上be動詞的用法的四個功能中，第一個功能最常見，第三個功能是考試的重點也是難點。為了方便大家對Be動詞用法的記憶，小編還給大家總結(jié)了be動詞的用法的常用口訣：我用am，你用are，is連著他，她，它;單數(shù)名詞用is，復(fù)數(shù)名詞全用are。
變疑問，往前提，句末問號莫丟棄。變否定，更容易，be后not莫忘記。疑問否定任你變，句首大寫莫遲疑。
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