<html><head><meta http-equiv="Content-Type" content="text/html; charset=gb2312"><link rel="stylesheet" href="home.css" tppabs="home.css"><link rel="stylesheet" href="eng.css" tppabs="eng.css"></head><body bgcolor="white" text="black" topmargin="10" leftmargin="0" marginwidth="0" marginheight="0"><table width="540" border="0" cellspacing="0" cellpadding="0" align="center" height="15"><tr><td> </td></tr></table><div align="center"><table width="540" border="0" cellspacing="0" cellpadding="0"><tr><td colspan="3" class="p2" width="760"><b>21.13 带to 的情态动词</b></td></tr><tr><td height="254" width="20"> </td><td height="254" width="520" valign="top" class="p2"><br> 带to 的情态动词有四个:ought to, have to, used to, be to, 如加上have got to ,(=must), be able to,为六个。它们的疑问,否定形式应予以注意:<br> Do they have to pay their bill before the end of the month?<br> She didn't use to play tennis before she was fourteen.<br> You ought not to have told her all about it.<br> Ought he to see a heart specialist at once.?<br><br> ought to 本身作为情态动词使用。其他的词作为实义动词使用,变疑问,否定时,须有do 等助动词协助。<br><br>典型例题<br> Tom ought not to ___ me your secret, but he meant no harm. <br> A.have told B.tell C.be telling D. having told<br> 答案A。由于后句为过去时,告诉秘密的动作又发生在其前因,此地应用过去完成时,但它在情态动词 ought to 后,所以用have。<br> <br></td></tr></table></div></body></html> |