選修二unit1過去完成時構(gòu)成肯定句：主語+had+done否定句：主語+hadnot+done...一般疑問句：Had+主語+done...?特殊疑問句：疑問詞+had+(主語+)done...?用法1、表示在過去某個動作或時間之前已經(jīng)發(fā)生或者完成的動作，即“過去的過去”，常用by,before等引導(dǎo)的時間狀語從句連用。Theyhadconstructedanewbridgeinthevalleybytheendoflastmonth.Thecaptainhadcheckedalltheequipmentbeforetheshipsetsail.Bytheendoflastmonth,wehadfinishedhalfoftheproject.表示從過去某一時間開始，延續(xù)到過去另一時間的動作，常與for，since引導(dǎo)的時間狀語（從句）連用。Hetoldusthathehaddonethescientificresearchforfiveyears.Hesaidhehadmadegreatprogresssincehecamehere.表示過去未實現(xiàn)的計劃或者愿望，常用的動詞有：hope,expect,suppose,think,want,intend,mean,plan等。Hehadwantedtohelpyoubuthehadnotimethen.Ihadneverthoughtthatyouwerewillingtohelpme.用于“This/Itwasthefirst/second...timethat...”“Itwas+一段時間+since從句”“Thiswasthe+形容詞最高級+名詞+從句”等句型中，從句用過去完成時。Itwasthefirsttimethathehadorganizedsuchanadventuretrip.Itwasfivemonthssincehehadreturned.ThiswasthebestadvicethatIhadevergiventomyfriend.在hardly/scarcely...when...和nosooner...than...等結(jié)構(gòu)中，主句一般使用過去完成時，從句用一般過去時。當(dāng)否定副詞hardly,scarcely,nosooner位于句首時，主句采用部分倒裝。HardlyhadIfinishedtheworkwhenthelightwentout.Nosoonerhadshearrivedthanshedevotedherselftoherresearch.在表示過去動作先于主句動作發(fā)生的賓語從句中，用過去完成時。HetoldmehehadwatchedthesunriseatthetopofMountTai.在條件狀語從句中，表示與過去事實相反的假設(shè)時，從句要用過去完成時。Ifyouhadhelpedme,Iwouldhavegotahighscore.重難點提示過去完成時和現(xiàn)在完成時的區(qū)別過去完成時和現(xiàn)在完成時，都可以跟表示一段時間的狀語連用，如foraweek，fortthreeyears,foralongtime。但現(xiàn)在完成時表示在過去開始并延續(xù)到現(xiàn)在的動作，句中不能有明確的過去時間狀語。而過去完成時則表示在過去某一時間開始并延續(xù)到過去某個時間的動作，句中含有表示截止到過去的時間狀語。比較：Shehasbeenillforaweek.Shehadbeenillforaweekbeforeshecameback.Everythinghasgonewelluptonow.Everythinghasgonewelluptothattime.在含有時間狀語從句的復(fù)合句中，尤其是before和after,assoonas引導(dǎo)的從句，它們已經(jīng)表明了主句和從句謂語動詞發(fā)生的先后，所以在先的那個動作可以不用過去完成時。I(had)closedthewindowbeforehelefttheroom.Afterhe(had)lefttheclassroom,theteachercamein.ago和beforeago指以現(xiàn)在為起點的一段時間以前，謂語動詞用一般過去時；before指以過去為起點的一段時間以前，謂語動詞往往使用過去完成時。強化練習(xí)Thiswasn’tthefirsttimewe_______________(trap)intoasituationlikethis.HesaidthatChina_______________(commit)tothegradualmarketreforminthepastyears.Groupsofnew,modernbuildings______________(springup)alongtheriverby2020.Thisresearchwork______________(absorb)himforseveralyearsbeforehefinallyquitit.Hardly________she_________(hear)thecriticismwhensheburstintotears.Ididn’tmeetthelinguistintheuniversity.HowIwishI___________(see)him!Wewererelievedtolearnthatallthewinners____________(rescue)fromtheaccident.I____________(hope)tosendPeteragifttocongratulatehimonhismarriage,butIcouldn’tmanageit.BeforehearingfromZac,Adelinehadn’trealizedthemedalwasmissing.Likemanymilitarymeda