初中英語語法:英語語法大全之帶to的情態(tài)動(dòng)詞

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《英語語法大全之帶to的情態(tài)動(dòng)詞》由留學(xué)英語組編輯整理(www.liuxue86.com)。本內(nèi)容整理時(shí)間為05月12日,如有任何問題請(qǐng)聯(lián)系我們。
    帶to的情態(tài)動(dòng)詞
    帶to的情態(tài)動(dòng)詞有四個(gè):ought to, have to, used to, be to, 如加上have got to ,(=must), be able to,為六個(gè)。它們的疑問,否定形式應(yīng)予以注意:
    Do they have to pay their bill before the end of the month?
    She didn't use to play tennis before she was fourteen.
    You ought not to have told her all about it.
    Ought he to see a heart specialist at once.?
    ought to 本身作為情態(tài)動(dòng)詞使用。其他的詞作為實(shí)義動(dòng)詞使用,變疑問,否定時(shí),須有do 等助動(dòng)詞協(xié)助。
    典型例題
    Tom ought not to ___ me your secret, but he meant no harm.
    A.have toldB.tellC.be tellingD. having told
    答案A。由于后句為過去時(shí),告訴秘密的動(dòng)作又發(fā)生在其前因,此地應(yīng)用過去完成時(shí),但它在情態(tài)動(dòng)詞 ought to 后,所以用have。
    《英語語法大全之帶to的情態(tài)動(dòng)詞》由留學(xué)英語組編輯整理(www.liuxue86.com)