初中英语语法知识点整理总结-数词-

数词分类：数词有基数词和序数词两种。英语的数词可以作句子的主语、宾语、表语和定语。一）.基数词：表示数目的词叫基数词。1、英语中常用的基数词有：123456789101112onetwothreefourfivesixseveneightnineteneleventwelve13141516171819thirteenfourteenfifteensixteenseventeeneighteennineteen2030405060708090100twentythirtyfortyfiftysixtyseventyeightyninetyone(a)hundred2335101twenty-threethirty-fiveonehundredandone1000→one(a)thousand,10000→tenthousand,100000→onehundredthousand,1000000→onemillion,10000000→tenmillion,100000000→onehundredmillion,108→onehundredandeight,146→onehundredandforty-six,500→fivehundred,1001→onethousandandone,1813→onethousandeighthundredandthirteen.[注意]：(1)百位与十位之间要加and；十万位和万位,亿位和千万位之间通常也要加and。(2)英语用千、百万等单位计数,大数字从右向左看,每隔三位划一逗号,倒数第一个逗号之前要用thousand,倒数第二个逗号之前要用million,倒数第三的逗号之前要用billion表示。(3)hundred、thousand、million作数词时,不用复数,前面可以加上one,two,…等其它数词。用作名词时复数表示“成…上…”,后面必须要有of,前面可以加上some,many,several等词。如：fivehundred(五百),hundredsof(成百上千的),tenthousand(一万),thousandsof(成千上万的),millionsof(成百万的)二）.序数词：表示顺序的数词叫序数词。1、英语的序数词基本变法：(1)一般在基数词后加th,(2)-ve结尾的改为-fth,(3)-ty结尾的改为-tieth,(4)熟记特殊词。2、序数词如下：1st2nd3rd4th5th6th7th8th9th10th11th12th※first※second※thirdfourthfifthsixthseventheighthninthtentheleventhtwelfth13th14th15th16th17th18th19ththirteenthfourteenthfifteenthsixteenthseventeentheighteenthnineteenth20th30th40th50th60th70th80th90th100thtwentieththirtiethfortiethfiftiethsixtiethseventietheightiethninetiethoneundredth21st22nd23rd35th101sttwenty-firsttwenty-secondtwenty-thirdthirty-fifthonehundredandfirst1000th→onethousandth,1000000th→onemillionth.,第703→thesevenhundredandthird,第5480→thefivethousandfourhundredandeightieth.3、注：(1)两位以上的序数词仅个位数部分用序数词,其余部分仍用基数词。如：thirty-sixth,(2)使用序数词时一般加定冠词the.如：I’minthethirdgrade.(3)序数词作“几分之几”讲时,有复数形式。如：1/5→onefifth;2/3→twothirds;4/7→foursevenths;1/2→ahalf;1/4→aquarter;3/4→threequarters;50%→fiftyhundredths(fiftypercent).4、数词的用法：1)表示年份：2002:twentythousandandtwo;1976:nineteenseventy-six.2)表示日期：12月1日:Dec.1st或thefirstofDecember；2002年11月8日:Nov.8th,2002.3)表示时刻：5：15→fivefifteen或aquarterpastfive;8：30→eightthirty或halfpasteight;10：45→tenforty-five或aquartertoeleven.4)表示编号：Room105→Roomone0five;BusNo.13→BusNumberThirteen;P.5→PageFive;Tel.No.7658659→TelephoneNumberseven-six-five-eight-six-five-nine5)小数的读法：5.7→fivepointseven,0.16→zeropointonesix.6)6、“半”的表达：1/2→half,半小时→halfanhour,1.5小时→oneandahalfhours或onehourandahalf.序数词前面加the时,表示顺序,加a/an时表示“再一、又一”。如：Thethirdlessonisratherdifficult.(第三课相当难)/Shallwereadthetextathirdtime?(我们把课文读第三遍,好吗？