什么是英語助動(dòng)詞？有何作用？

　　助動(dòng)詞的英語的是Auxiliary verbs

　　英語里有三個(gè)助動(dòng)詞：他們分別是be, do 和 have.

　　助動(dòng)詞一般出現(xiàn)主動(dòng)詞前。注意是一般情況。

　　分別講一下三個(gè)助動(dòng)詞的功能

　　Auxiliary be = 助動(dòng)詞Be

　　功能：用來表示進(jìn)行時(shí)和被動(dòng)語態(tài)

　　例句：I’m waiting for Sally to come home. (進(jìn)行時(shí))

　　Her car was stolen from outside her house. (被動(dòng))

　　Auxiliary do = 助動(dòng)詞do

　　功能：用來構(gòu)成和表示疑問句，否定句和強(qiáng)調(diào)。

　　例句：Does she live locally? (疑問)

　　They didn’t know which house it was. (否定)

　　I do like your new laptop! (強(qiáng)調(diào))

　　Auxiliary have = 助動(dòng)詞have

　　功能：用來構(gòu)成和表示完成時(shí)。

　　例句：I’ve lost my memory stick. Have you seen it anywhere? (現(xiàn)在完成)

　　She had seen my car outside the shop. (過去完成)

　　助動(dòng)詞一般和主動(dòng)詞連用，剛才說是一般情況，是不是也有獨(dú)立出現(xiàn)的情況呢?

　　例子：A:Does she play the clarinet?

　　B:Yes, She does. = (Yes, she plays the clarinet.)

　　A:It hasn’t snowed at all this year, has it?

　　:No, it hasn’t. = (No, it hasn’t snowed.)

　　獨(dú)立出現(xiàn)和使用的助動(dòng)詞，這里相當(dāng)于一個(gè)主動(dòng)詞。

　　通過比較觀察，be|do|have作為助動(dòng)詞和主動(dòng)詞使用的區(qū)別。

　　例子：beShe’s a professional photographer.(主動(dòng)詞)

　　He’s thinking of moving to New Zealand.(助動(dòng)詞)

　　doI need to do some work this evening.(主動(dòng)詞)

　　Do you like Thai food, Jim?(助動(dòng)詞)

　　haveThe children have lunch at twelve o’clock.(主動(dòng)詞)

　　We haven’t been to the cinema for ages.(助動(dòng)詞)

　　它們?nèi)齻€(gè)做主動(dòng)詞，是用來構(gòu)成問句和否定句。