数词一基数词和序数词基数词（表数量，后面常跟名词复数，1除外）11到12是各自独立的形式2从13~19均是后缀-teen结尾，特殊拼写的词：thirteen,fifteen,eighteen3从20~90的整十数词均以后缀-ty结尾。表示几十几时，个位和十位之间加不加连字符均可。如：thirty-one/thirtyone序数词（表顺序，后面常跟名词单数，前面一般有the或代词修饰）1大部分加th，特殊形式：first,second,third,fifth,eighth,ninth,twelfth.2以ty结尾的表示几十的基数词，先变y为i，再加-eth.如twenty-twentiethforty-fortieth3表示两位以上非整数基数词变为序数词时，只变个位数。twenty-one–twenty-firstonehundredandthree-onehundredandthird4其他情况均在词尾加-thten-tenthonehundred-onehundredth写出下列数字的基数词的序数词1one2two3three4four5five6six7seven8eight9nine10ten11eleven12twelve13thirteen14fourteen15fifteen16sixteen17seventeen18eighteen19nineteen20twenty21twenty-one用法:1.基数词+名词复数The+序数词+名词单数eg:IhavetwobooksTherearetwelvemonthsinayear.JanuaryisthefirstmonthoftheyearEx:1.Thereare___studentsinourclass.A.fiftiethB.fifty-fiveC.fiftyfiveD.fivety2.Thereare__daysinaweek.Mondayisthe_day.A.seven,twoB.seven,secondC.theseventh,two3.Thebuildinghas___floors.Heliveson___floor.A.twelve,twelfthB.twelfth,twelveC.twelve,thetwelfthD.twelve,twelve4.Thereareninety__here.A.personB.peopleC.man用法：2．Hundred，thousand，million，billion百千百万十亿与具体数字连用时，不加s和of，否则加s和ofEg:twohundredbooks/hundredsofbooksthreethousandtrees/thousandsoftreesEx.1.Eight___peoplecametovisitheretoday.A.hundredofB.hundredC.hundredsof2.Weplanted___treeslastweek.A.3hundredB.hundredofC.3hundreds3.Therearemany___starsinthesky.A.thousandB.thousandofC.thousandsof二钟点的表达1小时、分钟、秒钟要用基数词6:00It’ssix(o’clock)2几点过几分，小于等于半小时用介词past。4:05-fourpastfive8:15-fifteenpasteight9:30-halfpastnine3几点差几分，用介词to。6:45-aquartertoseven6:40-twentytoseven4读法2:05-twoofive3:15-threefifteen*注意习惯表达方式halfanhour,halfakilo,onehourandahalf=oneandahalfhours,twoandahalfkilos=twokilosandahalf,oneortwodays=onedayortwo三分数、小数、百分数、度数1分数：分子用基数词，分母用序数词，分子是1时分母用单数，分子大于1时序数词+s1/3onethird3/4threefourths/threequarters2小数：小数点用point0.3zeropointthree7.14sevenpointonefour3百分比：百分比用percentorpencentage60%sixtypercentsixtypercentages4度数：度数用degree,大于1用加s1℃onedegree20℃twentydegrees四年、月、日的表达顺序：月–日–年in1998inMay,1998onMay4,1998onMay4th,1998五编号的表达：名词＋基数词=the+序数词+名词单数Eg:class7/room101/busNo.7Lessonone=thefirstlesson六其他重点表达在20世纪90年代inthe1990s在他30多岁inhisthirties一段5分钟的步行afive-minutewalk=fiveminutes’walk一座800米长的桥an800-metre-longbridge
