人教版八年级英语上主将从现

八年级上语法专项----主将从现一、如果主句是将来时或表示将来含义时，那么条件和时间状语从句多用一般现在时如：WhenIgrowup,Iwillbeanurseandlookafterpatients/Iwanttobeanurseandlookafterpatients.我长大后要当一名护士，照顾病人。二、如果主句是祈使句，那么从句通常要用一般现在时如：Don’tlaughatmewhenImakeamistake.我犯错误的时候不要笑话我。三、如果主句是含有情态动词的一般现在时，根据需要从句多用一般现在时如：Youshouldbequietwhenyouareinthereadingroom在阅览室时应保持安静。四、主将从现说的是在含有时间状语从句和条件状语从句的主从复合句中，如果主句的时态是一般将来时，那么从句要用一般现在时。例如：Iwilltellhimaboutitwhenhecomes.Ifitisfinetomorrow,wewillgoouting.五、如果主句的时态是过去将来时，那么从句要用一般过去时。例如：Hesaidthathewouldhaveanothertryifhehadthechance.Iknewhecouldhelpmeifhewasfreethenextday.主要标志有：if、unless、until、when、assoonas等注意if条件句的时态搭配：1．if从句用一般现在时，主句用一般将来时Ifherunshe’llgetthereintime.如果他用跑的，他就会及时赶到那儿。Thecatwillscratchyouifyoupullhertail.如果你拉猫的尾巴，它就会抓你。2．if从句用一般现在时，主句用may/might/canIfthefoggetsthickertheplanemay/mightbediverted.如果雾在大一些，飞机可能就会改在别的机场降落。Ifitstopssnowingwecangoout.如果雪停了，我们就可以出去。3．if从句用一般现在时，主句用must/shouldIfyouwanttoloseweightyoumust/shouldeatlessbread.如果你想减肥，你必须少吃面包。4．if从句用一般现在时，主句用一般现在时Ifyouheaticeitturnstowater.(也可用willturn)如果把冰加热，它就会化成水。4．if从句用现在进行时，主句用一般将来时IfyouarelookingforPeteryou’llfindhimupstairs.如果你是在找彼得，上楼就会找到他。if引导的条件状语从句专项练习Ⅰ.单项选择（）1.Ifyou_____totheparty,you’llhaveagreattime.A.willgoB.wentC.goD.going（）2.I____hertheanswerifshe____me.A.cantell,willaskB.willtell,willaskC.wouldtell,askD.willtell,asks（）3.–Whatareyougoingtodotomorrow?--We’llgotothelibrarytomorrowifit___.A.isn’trainB.rainC.won’trainD.doesn’train（）4.Whatwillyoudoifyou_____totheoldfolk’shome?A.goB.wentC.goingD.willgo（）5．I’llgivethebooktohimifhe___herenextSunday.A.willcomeB.comesC.iscomingD.cameⅡ.用所给词的适当形式填空6..Ifyou________(feel)tired,you_______________(have)tohavearest.7.Where_______he_________(see)thefilmifhe________________(have)time?8.Ifthere__________(be)fewertrees,there_______________(be)morepollution.9.IfMarcia_____________(live)alone,she___________________(keep)apetparrot.11.Lana________________(buy)anewdressiftheoldone____________(be)outofstyle.12.Thetwins______________(fight)ifthey_______________(argue).13.I____________(have)abakesaleifI_____________(need)moneyforeducation.14.Peter_____________(send)meabeautifulsouvenirifhe________________(tour)Spain.15.I____________(go)tothebeachifit________________(notrain)thisweek.17.__________they__________(have)amatchiftheP.E.teacher_____________(be)busy?18.Ifshe____________(get)uplate,she_____________(notcatch)theearlybus.