助動詞本身沒有獨立的意義,在句中不能作獨立謂語,只能和主要動詞一起構成謂語,表示時態、語態、人稱、數和否定疑問的語法特征。助動詞有be,do,have,shall,will,should, would等。如:
Do you speak English?
你說
英語嗎?(疑問句)
He was still doing his homework at10pm last night.
他昨晚上10點還在做作業。(過去進行時)
The professor was invited to visit the school in Beijing.
這個教授被邀請參觀北京的某個學校。(被動語態)
助動詞的用法有以下幾點:
(1)助動詞be的用法
?、贅嫵蛇M行時態,如:
What were you doing this time yesterday evening?
昨天晚上這個時候你在做什么?
I am listening to a piece of music now.
我現在正在聽音樂。
?、跇嫵杀粍诱Z態,如:
He was invited to the dance ball last week.
他上周被邀參加舞會。
preparations are being made for the speech contest(比賽).
講演比賽的準備工作正在進行。
③和動詞不定式構成謂語,表示按計劃安排要發生的事。如:
Where are we to meet?
我們在哪里碰頭?
I was to stay at home with my sister
我和我妹妹待在家里。
(2)助動詞have的用法
have+過去分詞構成完成時的肯定式、否定式和疑間式。如:
I have already seen this film.
我已經看過這部電影了。
He had lived in China for ten years before his mother came.
在他媽媽來之前,他已在中國生活十年。
(3)動詞do的用法
?、贅嫵梢话銜r的疑問式或否定式。如:
Do you come to work on foot every day?
你每天走著上班嗎?
Don't be late next time.
下次別遲到了。
?、诩訌娬Z氣。如:
Do come and join us.
千萬要來參加我們的活動。
I do think you should go.
我的確認為你應該去。
?、鄞媲懊鎰偝霈F過的動詞,以避免重復。如:
Do you like music?Yes,I do.
你喜歡音樂嗎?是的,我喜歡。
I went to the concert yesterday.So did she.
我昨天去音樂會了,她也去了。
?、軜嫵傻寡b句。如:
Only then did I understand what he meant.
只有到那時,我才知道他的意思。
Never did he go there again.
他再也沒去過那里。
(4)助動詞shall和will的用法
shall/will+動詞原形構成將來時態。shall在陳述句中只用于第一人稱,will可用于所有人稱。如:
Tomorrow I shall finish the work.
明天我將完成這項工作。
We shall/ will be glad to see you.
我們將很高興見到你。
(5)助動詞 should和 would的用法
?、賡hould是shall過去式, would是will的過去式。 should/ would+動詞原形構成過去將來時。 should用于第一人稱, would用于所有人稱。如:
He asked us when we should have the basketball match.
他問我們什么時間將舉行球賽。
I told him I would wait for him outside.
我告訴他我在外面等他。
②構成虛擬語氣。如:
If he were here, everything would be all right.
要是他在這里,一切都沒有問題了。
If I hadn't taken your advice,I would have made a bad mistake.
如果不聽你的話,我就犯大錯了。
