【正文】
對現(xiàn)在和將來的假設用過去時,對過去的假設用過去完成時。例如: 1)You must e to the classroom before eight. 2)It is raining hard outside, but I have to leave now. 3)“Must we do it now?” “No, you needn’t.” 6. used to +do, be used to +doing和be used to +do (1)used to +v意為“過去常?!?,“過去一直”;be used to +ving / n(名詞)意為“習慣于”;be used to +v意為“被用來(做某事)”。 be able to表示主觀意愿,強調要克服困難去做某事。句型 情態(tài)動詞dare 實義動詞 dare 肯定句 現(xiàn)在時 dare to 少用過去時 dare to 少用 現(xiàn)在時 dare/dares to do過去時 dared to do 否定句 現(xiàn)在時 daren’t/dare not do過去時 dared not do 現(xiàn)在時 do/does not dare (to) do過去時 did not dare (to) do 疑問句 現(xiàn)在時 Dare he do? 過去時 Dared he do? 現(xiàn)在時 Do you/Does he dear (to) do? 過去時 Did he dare (to) do 3. can 和 may考試中主要測試can,may或could,might表示可能性的區(qū)別及對may構成的疑問句的回答。例如: 1)He must be playing basketball in the room. 2)She may be staying at home. 三、情態(tài)動詞+動詞完成進行式 情態(tài)動詞+行為動詞完成進行式(即情態(tài)動詞+ have been + ving 形式),表示推測或評論過去某動作是否正在進行或一直在進行。例如: 1)With all the work finished, I should have gone to the party last night. 2)You ought not to have made fun of him. He is not the one you laugh at but learn from. 5. needn’t have done needn’t have done 表示過去做了某事,但沒有做的必要, 意為“本沒必要…”。 1. must have donemust have done 表示對過去某事的肯定猜測。情態(tài)動詞與其他動詞連用表示說話人的語氣。 I have to cook for my child. 我得給孩子做飯。 You should hand in the exercise book. 你應該交作業(yè)本兒了。 He said he would help me. 他說他會幫助我。ll do my best to catch up with them. 我要盡全力趕上他們。 You ought not to have taken the book out of the readingroom. 你不應該把書帶出閱覽室。指過去動作,表示一件事情該做而未做。 ought 應當,應該 后面跟帶有 to 的動詞不定式。 The little girl dare not speak in public. 小女孩不敢在公眾面前說話。t + have + 過去分詞 表示過去做了沒必要做的事情。 need 是一個情態(tài)動詞, 他的用法完全和其他情態(tài)動詞一樣, 但 need 還可當作實義動詞使用, 這時 need 就象其他動詞一樣,有第三人稱,單復數, 后面加帶 to 的動詞等特性。 must 和 have to 的區(qū)別: must 表示說話人的主觀思想, have to 表示客觀需要。 He must have received my letter now. 他現(xiàn)在一定收到我的信了。 He had to go because of some