协助主要动词 构成谓语的词叫助动词(Auxiliary Verb)，也叫辅助动词。被协助的动词称作主要动词(Main Verb)。以下是小编整理的关于助动词的实用方法，希望大家认真阅读!
1助动词be
一般疑问句：
陈述句变为一般疑问句时,如句中有be动词(am/is/are/ was/were),可直接将它们提至主语前。
如主语为第一人称,应将其改为第二人称。例如：
I'm watching TV.
Are you watching TV?
如主语为第三人称，那么单数用is，复数用are。
例如：
He is good at swimming
Is he good at swimming?
My classmates are kind and polite.
Are your classmates kind and polite?
时态为一般过去时，例如：
He was an engineer.
Was he an engineer?
They were on a long journey.
Were they on a long journey?
特殊疑问句：
特殊疑问句有两种语序：
如疑问词作主语或主语的定语，即对主语或主语的`定语提问，其语序是：
“特殊疑问词+陈述句”，例如：
Alice is singing in the room.
Who is singing in the room?
如疑问词作其他成分，即对其他成分提问，其语序是：
“特殊疑问词+一般疑问句”，例如:
He is from Canada.
Is he from Canada?
Where is he from?
2助动词do
一般疑问句：
陈述句变为一般疑问句时,如句中只有一个实义动词作谓语时，句首加do或does，主语后的实义动词用原形。
例句：
I want to have a haircut.
Do you want to have a haircut?
She like that red car.
Does she like that red car?
时态为一时般过去时，则在句首加did，主语后的实义动词用原形。
例句：
She came by train.
Did she come by train?
特殊疑问句：
特殊疑问词+一般疑问句，例如:
He plays basketball every night.
Does he play basketball every night?
What does he do every night?
3助动词have
一般疑问句：
在现在完成时中，陈述句变为一般疑问句则需将has/have提前，放在句首。
例句：
I have finished my homework.
Have you finished your homework?
He has changed his mind.
Has he changed his mind?
特殊疑问句：
特殊疑问词+陈述句，例如：
He has cleaned the room yesterday.
Who has cleaned the room yesterday?
特殊疑问词+一般疑问句，例如：
I have studied English for three years.
Have you studied English for three years?
How long have you studied English?
4助动词shall和will
注意：Shall只用于第一人称，如用于第二、三人称，就失去助动词的意义，变为情态动词，且有命令意味。
变为一般疑问句，只需将shall和will提前至句首。例如：
We should study harder at English.
Should we study harder at English?
He will go to Shanghai.
Will he go to Shanghai?
变为特殊疑问句，例句：
I shall look after the sheep.
Who shall look after the sheep?
She will go to Beijing tomorrow.
When will she go to Beijing?
5助动词should和would
should无词义，只是shall的过去形式，只用于第一人称;
would也无词义，是will的过去形式。
用法与shall，will相似，只是shall，will表示一般将来时，should，would表示过去将来时。
注意：这里的shall,will,would,should只作助动词使用，无词义，而非情态动词。
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