选修6 unit3语法

GrammarTheuseof“it”Talkaboutthefollowingpictures,usingItisnouse/gooddoingsth做…没有用/不好Itisfundoingsth做……很有趣还想跑？甭想！想追我?没门！①Itisnevertoooldtolearn.活到老,学到老。②Itiseasiertofallthantorise.摔倒容易爬起来难。③Itisnousecryingoverspiltmilk.覆水难收。④Itneverrainsbutitpours(泼水).不鸣则已,一鸣惊人。⑤Itiseasytoopenashopbuthardtokeepitalwaysopen.创业容易守业难。⑥Ittakesthreegenerations(代)tomakeagentleman.十年树木,百年树人。Proverbs(谚语)with“It”Readandanalyzethesentences.ItisFridaytoday.ItwasverycoldlastMonday.Itisabout8:30now.Itisabout25kmfromLongxiantoBazi.ItliesinthesouthofShaoguancity.Itis40°C!Yougotahighfever!Conclusion:it可以用作非人称代词,表示_____,_____,______,______,______,______等。dateweathertimedistanceplacetemperature日期天气时间距离地点温度Itisobviousthatthewaterwastoblame.Itistruethathewilltreatmetobreakfasttomorrow.Itiscertainthatourclasswilldoagoodjobinthefinalexam.Isitpossiblethathewillbecomethechairmanofourcountry?ItisamazingthatatmyageIstilllooklikeastudent!分析:it是__________,句子真正的主语是___________________。Readandanalyzethesentences.形式主语that引导的主语从句思考:为什么要用it做形式主语而把真正主语放到后面去?遵循英语语言的尾重原则,避免句子头重脚轻。Theuseof“it”一、it作人称代词1.it的最基本用法是作代词，主要指刚提到的事物，以避免重复:Xi’anisabeautifulcity,isn’tit?2.也可以指动物或婴儿(未知性别的婴儿或孩子):Isthisyourdog？No,itisn’t.二、it作非人称代词it有时并不指具体的东西，而泛指天气、时间、日期、距离、价值、度量、温度、环境等，1.指天气：Itisalovelyday,isn’tit?2.指时间:Itwasnearlymidnightwhenshecameback.3.指环境:Itwasveryquietinthecafé.4.指距离：Itishalfanhour’swalktothecitycentrefrommyhome.5.指日期：--What'sthedatetoday?--It'sMay1,2007.6.指季节：Itissummernow.7.指度量：Itisabout5kilograms.8.指价值：--What'sthecostoftheT-shirt?--Itis150yuan.三、it用作形式主语替代作主语的从句、动词不定式、动名词，而把真正作主语的从句、动词不定式、动名词置于句尾。1.替代作主语的动词不定式1)Itisadj.(forsb.)todosth.此处adj.通常为描述事件的形容词:easy,difficult,hard,necessary,impossible,right,wrong,important,polite,clear,obvious,certain,dangerous…Eg：Itisillegal(forateenager)todriveacarwithoutalicense.2)Itisadj.ofsb.todosth.此处adj.通常为描述人的形容词:kind,nice,rude,cruel,considerate,careful,silly,foolish,stupid,clever,wise,crazy...Eg：It‘skindofyoutohelpmewiththeproblem.2.It替代作主语的动名词的常见句型It’snogood/usedoing…It’s(well)worthdoing…It’s(well)worthwhiledoing/todoEg：It’snousecryingoverspiltmilk.3.it作形式主语替代主语从句①Itisadj.+clauseItisclear(obvious,true,possible,certain…)that...该句型中it是形式主语,真正的主语是that引导的主语从句,常译为“清楚(显然,真的……)”,是主语从句最常见的一种结构。Eg.Itisveryclearthathe’sroundandtalllikeatree.②Itisv-edthat…=sb./sth.istodoItissaid(reported/learned/believed/thought/known/told/hoped.....)that...该句型中的it仍是形式主语,真正主语是that引导的主语从句;该结构常译为“据说(据报道,据悉…)”。Eg:ItissaidthathehascometoBeijing.③Itis+noun+从句Itisapity(ashame/anhonor/agoodthing/afact/asurprise/...)that...该句型中,that后的从句一般用虚拟语气(should+动词原形),should可省去。表示出乎意料,常译为“竟然”。没有这种意义时,则不用虚拟语气。如：Eg:Itisapitythatsuchathing(should)happeninyourclass.这种事竟然发生在你们班上,真是遗憾Itisapitythatheisill.他生病了,真遗憾！④Ithappens(seems,looks,appears)that…该句型中it是形式主语，that引导的是主语从句，主句中的happen,seem等词是不及物动词。Eg：Itseemsthathewillbebackinafewdays.看来他再过几天才能回来。it做形式主语的几种特殊句型①Itistime(abouttime,hightime)that…that后的从句应该用虚拟语气，①常用过去时态表示虚拟。②有时也用should+动词原形，should不能省，常译为“是（正是）…的时候了”Eg:Itistimethatchildrenshouldgotobed.=Itistimethatchildrenwenttobed.孩子们该睡了。②Itisthefirst(second…)timethat…如果是is，后面的从句用现在完成时态；如果是was，后面从句则用过去完成时态，该结构中that可以省去；it有时用this/that替换,常译为“是第一（二）…次做…”。Eg:ItisthefirsttimeIhavebeenhere.这是我第一次到这里来。③Ittakessb.sometimetodosth.做某事要花费某人一些时间。Eg:Ittookmefivedaystosolvetheproblem.解决这个问题花了我五天时间。④Itcostssb.somemoneytodosth.做某事要花费某人一些钱。Eg:Itwillcostmyfatherfivethousandyuantobuysuchacomputer.买这台电脑花了我父亲5000元。⑤It’suptosb.todosth.应由某人（负责）做~~~Eg:Itisuptoyoutodecidewhethertotakethejobornot.做不做这份工作由你决定。四、it作形式宾语①当复合宾语中的宾语是不定式、动名词、宾语从句时,往往把宾语放在它的补足语后面，而用it作形式宾语,放在宾语补足语之前。常用的动词有think,believe,make,find,consider,feel等。Eg：Ithinkitnousearguingwithhim.我认为和他争吵没有用。②It用在不能直接跟宾语从句的动词后面，尤其是表示好恶的动词enjoy/like/love/appreciatedislike/hate/resent(憎恨)Eg：Ihateitwhenitrains我讨厌下雨的时候③answerfor(承担…的后果)，counton(期待)，dependon(依靠)，insiston(坚持主张，坚决要求)，seeto(确保)等。Eg：Iamcountingonitthatyouwillcome.我期待你会来。五用于强调句型中Itis/was+被强调部分+that/who...Itisnotuntil+被强调部分+that...Itwasfiveo’clock_________Igothome.Itwasatfiveo’clock_______Igothomewhenthat六、it常用的固定搭配1.makeit在口语当中相当于succeed,表示:成功、做到、说定、赶上、及时到达Eg:It'shardtomakeittothetopinshowbusiness.2.takeit/thingseasy相当于Don’tworryordon’thurry.用来劝告别人,表示“不要慌,别担心,沉住气”Eg:Takeiteasy！Hewilldoitwell.3.Italldepends/thatalldepends在口语中,相当于ithasn‘tbeendecidedyet,表示“那得看情况,还没有定下来”Eg:—Areyougoingtothecountrysideforholiday?—It/Thatalldepends.【当堂检测】完成句子1.Itisnogood_______________________(吃很多垃圾食品)。(have)2.Itis________________(你的能力重要),notwhatyouareandwhereyouarefrom____(matter)3.Itistenyears____________________________(自从我们最后一次见面)。(since)4.Itis(high)time__________________________(他落实计划)。（carry）5.Hethinks_______tolearnEnglishwell.他认为学好英语很简单。6.____________discussingwiththem.跟他们讨论是没用的。havingmuchjunkfoodyourabilitythatthatsincewemetthelasttimethathecarryouttheplaniteasyItisnouse1.Hedidn’tmake____clearwhenandwherethemeetingwouldbeheld.(天津2007)A.thisB.thatC.itD.these2.____isourbeliefthatimprovementsinhealthcarewillleadtoastronger,moreprosperouseconomy.(浙江2006)A.AsB.ThatC.ThisD.ItCD课后巩固3.ThedoctoradvisedVerastronglythatsheshou