(大学英语语法讲解.pptVIP

大学英语语法讲解 Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0. Copyright 2004-2011 Aspose Pty Ltd. 情态动词的完成时(表示对过去的说法) must +have +过去分词 （用于肯定句）一定已经……. The light is still on. They must have forgotten to turn it off when they left the room. 注:mustn’t have done × Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0. Copyright 2004-2011 Aspose Pty Ltd. can’t (couldn’t) +have +过去分词 （用于否定或疑问句）不可能…….. He cannot have been to that town for I saw him just now. Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0. Copyright 2004-2011 Aspose Pty Ltd. should/ought to +have+过去分词 本应该做(却没有做)……. As his best friend, you should/ought to have helped him. (but in fact, you didn’t.) Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0. Copyright 2004-2011 Aspose Pty Ltd. shouldn’t /ought not to +have +过去分词 本不应该做(却做了)……. You shouldn’t have parked your car here, for it’s a public place. Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0. Copyright 2004-2011 Aspose Pty Ltd. needn’t +have +过去分词 本不必做…… You needn’t have waited for me. I told you yesterday I would overwork. Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0. Copyright 2004-2011 Aspose Pty Ltd. with with + done With the homework finished, the boy went out. with + doing With the old man leading the way, we finally find the house. Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0. Copyright 2004-2011 Aspose Pty Ltd. with + prep With the light on, all the students went out of the classroom. Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0. Copyright 2004-2011 Aspose Pty Ltd. 虚拟语气的用法 概念：表示说话人的愿望、假设、猜测、或建议，而不表示客观存在的事实。虚拟语气通过谓语动词的特殊形式来表示 Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0. Copyright 2004-2011 Aspose Pty Ltd. 虚拟语气用于条件状语从句 (1) 与过去事实相反 If…had +done, …would (sho