第四章 情態動詞（二）一、 情態動詞+動詞完成式
c. must have done
1.表示對過去事實有把握的推測，具有較大的可能性。只用于肯定句中，否定句和疑問句用cancould have done。
his watch must have stopped. 他的表肯定停了。
--- i rang your flat yesterday. a man answered but i didn't recognize the voice. 昨天我給你家打電話，一位男士接了電話，但我沒聽出來是誰的聲音。
--- oh, it must have been my brother peter. 哦，那一定是我哥哥彼得。
2.用于虛擬語氣中時，表示與過去事實相反。
you must have caught the bus if you had got up earlier. 如果你早一點兒起床的話，你準能趕上那一班公共汽車了。（事實上沒有趕上公共汽車）
he must have won the game if he had been careful enough. 如果他足夠細心的話，他準能贏得比賽。.
d. needn't have done
用于對過去的責備，表示“沒有必要做某事，可是做了”。
the airport is close to us. you needn't have hurried there early. 機場離這兒很近，你沒必要早早地趕到那里。（可是你早早地到那兒了）
he is still young. you needn't have sent him such an expensive present. 他還小，你沒必要送他這么昂貴的禮物。
注意：
如表示“過去不必做也沒有做”之意，需用didn't need to do。
it is not cold today. i didn't need to take the thick sweaters out. 今天天氣不冷，我沒有必要把厚毛衣拿出來。（實際上也沒拿）
e. shouldought to have done
1.表示對過去動作的責備或批評。
you should have gone over your lessons. (in fact you didn't go over your lessons.) 你們應把功課復習好的。（可事實上你們沒有。）
you shouldn't have watched tv last night. (in fact you watched tv last night.) 你們昨天晚上本不該看電視。（可你們看了。）
you oughtn't to have entered the teachers' office without permission. 沒有經過允許，你們本不該進老師的辦公室。
you oughtn't to have gone to the deserted place alone. 你不該獨自去那荒涼之地。
2.表示期待或推測。
if the flight was on time, you should ought to have arrived in shanghai early this morning. 如果航班準點的話，你今早就能到上海了。
the building should ought to have been completed by the end of the week. 這幢建筑物本周末前應該能完工。
f.would have done
表示與過去事實相反的假設或結果。
i would have been happy to see him, but i didn't have time. 我會很高興和他見面的，但我沒時間見他。
if your father had still been alive, he would have felt very proud of you. 你父親如果還健在的話，他會為你驕傲的。