小升初英语知识点精讲 100以内的基数词变序数词的规律

小升初英语知识点精讲100以内基数词变序数词的规律基数词：表示事物数量多少的词。序数词：表示顺序的数词。one,two,three…first,second,third…基数词变序数词：1-3onetwothreefirstsecondthird1－19基数词变序数词onetwothreeeightninefivetwelve其余的数词特殊变化1－19基数词变序数词onetwothreeeightninefivetwelve其余的基数词基数词变序数词：8和9eigheightht去最后一个字母加thninninthe去t加th:去e加ththth1－19基数词变序数词onetwothreeeightninefivetwelve其余的基数词基数词变序数词：5和12变ve为f，再加th.fitwelveveffththfifthtwelfth1－19基数词变序数词onetwothreeeightninefivetwelve其余的基数词其余的基数词有哪些？foursixseventeneleventhirteenfourteenfifteensixteenseventeeneighteennineteenthththththththththththth加th20－99基数词变序数词基数词变序数词：整十数twentythirtyfortyfiftysixtyseventyeightyninetyy变y为i，再加ethtwentytwentieththirtythirtiethforty?…………基数词变序数词：几十几20－99基数词变序数词twenty-onetwenty-twothirty-onethirty-twoforty-oneforty-two……twenty-onethirty-thirty-十位个位只变个位：twenty-firstonetwofirstsecond按要求写单词。eight（序数词）__________twelfth（基数词）___________eight要去掉t再加th，它的序数词是eighth；twelfth是将twelve末尾的ve变为f再加th，它的基数词是twelve.eighthtwelve单项选择。Thursdayisthe________dayofaweek.A.fourthB.fivethC.fifth星期四是一周的第五天，这儿的第五应用序数词fifth，所以选C。MybirthdayisonDecember__________.A.21thB.21stC.21ndA21的序数词只要将个位上的1变为序数词就可以了，所以它的简写应当是21st.BThe_______monthofayearisSeptember.A.nineB.ninethC.ninthB一年的第九个月是九月，第九应用序数词ninth，它是将基数词nine去掉末尾的e再加上th.C