It•1,指代时间,天气,距离,日期等
•It’saboutanhour’swalkfromheretothevillage
•ItwasnearlymidnightwhenIarrivedhome
•2,指代this,that•What’sthisinEnglish
•It’sacomputer
•3,指代无生命吴或性别不明,身份不明的人•Whatalovelybaby,isn’tit
•Someoneisknockingatthedoor,whocanitbe
•4,指代上文,即事件•Jimhasleft
Haveyouheardofit
•Itoldhimtoreadalot,butitdidn’thelp
•5,形式主语,代替不定式,动名词,从句•Itisnecessarytokeepthebalanceofnature
•Itisnousecryingoverspiltmilk
•Itiswell-knownthatTaiwanbelongstochina
•6,形式宾语,代替不定式,动名词,从句、•Ifounditnecessarytotellthetruth
•Ithinkitisnousearguingwithhimoverit
•Youmustkeepitinmindthatyouareastudent
强调句型•ItwasinthestreetthatIsawhimyesterday
•WherewasitthatIsawhimyesterday
Shedidn’tgotobeduntilherfathercameback
1)Notuntilherfathercamebackdidshegotobed
2)Itwasnotuntilherfathercamebackthatshewenttobed
1)Itwasnot___shetookoffh