it的用法及强调句型.ppt

文档介绍：it的用法及强调句型it的用法一、it作指示代词【完成句子】用one,ones,it,that,those填空(1)—Ican'tfindmywatch. —Youhaven'tfound______?Ifyouwanttobuyanew______,Isuggestyoubuy______madeinChina.(2)We'vegotabigcupandtwosmall______.(3),是同名同物,相当于the+名词;one指代上文提过的单数可数名词是同名异物,相当于a+名词;a/an+形容词+one等于a/an+形容词+名词;复数形式用onesthat后面常有后置定语,有特指意义,代替不可数名词或单数可数名词,相当于the+名词(4)Thebooksonthefirstshelfareeasierthan______onthesecondshelf.(5),相当于theones。【例句观察】—?—',常指小孩或身份不明的人。【例句观察】It'。【完成例句】根据语境补全句子(6)—Whattimeisitnow?—halfpastseven.(7)—springnowandit''sItisit可用以指代时间、季节、天气或距离。【注意】it指代时间时,有如下一些句型:(1)Itistimeforsth./(forsb.)todosth./that-从句(shoulddo/did,必须用虚拟语气)(2)Itis/hasbeen+sometime+since-从句(从句用一般过去时)(3)It/Thisisthefirst/second…timethat-从句(必须使用现在完成时)这是某人第……次做了某事。It/Thatwasthefirst/second…timethat-从句(必须使用过去完成时)例:①ItisthesecondtimethatshehasvisitedtheGreatWall. ②elatetoschool.(4)Itwas+时间点+when-::①过了5年他们才从北大毕业。ItwasfiveyearsbeforetheyfinallygraduatedfromBeijingUniversity.②不久,我们就要从我们学校毕业了。Itwon'tbelongbeforewegraduatefromourschool.(5)Itwas/willbe+sometime+before-从句过了/要过多久才……过不了多久就……二、it作形式主语【完成例句】(8)ispossibleformetomakeatouraroundtheworld.【结论】代替由不定式、动名词或从句所表示的真正主语。为平衡句子,通常把不定式作主语改为it作形式主语。It