小升初英語(yǔ)知識(shí)點(diǎn)精講100以內(nèi)基數(shù)詞變序數(shù)詞的規(guī)律

基數(shù)詞：表示事物數(shù)量多少的詞。序數(shù)詞：表示順序的數(shù)詞。one,two,three…first,second,third…基數(shù)詞變序數(shù)詞：1-3onetwothreefirstsecondthird1－19基數(shù)詞變序數(shù)詞onetwothreeeightninefivetwelve其余的數(shù)詞特殊變化1－19基數(shù)詞變序數(shù)詞onetwothreeeightninefivetwelve其余的基數(shù)詞基數(shù)詞變序數(shù)詞：8和9eigheightht去最后一個(gè)字母加thninninthe去t加th:去e加ththth1－19基數(shù)詞變序數(shù)詞onetwothreeeightninefivetwelve其余的基數(shù)詞基數(shù)詞變序數(shù)詞：5和12變ve為f，再加th.fitwelveveffththfifthtwelfth1－19基數(shù)詞變序數(shù)詞onetwothreeeightninefivetwelve其余的基數(shù)詞其余的基數(shù)詞有哪些？foursixseventeneleventhirteenfourteenfifteensixteenseventeeneighteennineteenthththththththththththth加th20－99基數(shù)詞變序數(shù)詞基數(shù)詞變序數(shù)詞：整十?dāng)?shù)twentythirtyfortyfiftysixtyseventyeightyninetyy變y為i，再加ethtwentytwentieththirty

thirtiethforty

?…………基數(shù)詞變序數(shù)詞：幾十幾20－99基數(shù)詞變序數(shù)詞twenty-one

twenty-twothirty-onethirty-twoforty-oneforty-two……twenty-onethirty-thirty-十位個(gè)位只變個(gè)位：twenty-firstonetwofirstsecond按要求寫單詞。eight（序數(shù)詞）__________twelfth（基數(shù)詞）___________eight要去掉t再加th，它的序數(shù)詞是eighth；twelfth是將twelve末尾的ve變?yōu)閒再加th，它的基數(shù)詞是twelve.【解析】eighthtwelve單項(xiàng)選擇。Thursdayisthe________dayofaweek.A.fourthB.fivethC.fifth星期四是一周的第五天，這兒的第五應(yīng)用序數(shù)詞fifth，所以選C。【解析】MybirthdayisonDecember__________.A.21thB.21stC.21ndA21的序數(shù)詞只要將個(gè)位上的1變?yōu)樾驍?shù)詞就可以了，所以它的簡(jiǎn)寫應(yīng)當(dāng)是21st.【解析】【錯(cuò)誤答案】【正確答案】易錯(cuò)1BThe_______monthofayearisSeptember.A.nineB.ninethC.ninthB一年的第九個(gè)月是九月，第九應(yīng)用序數(shù)詞ninth，它是將基數(shù)詞nine去掉末尾的e再加上th.【解析】【錯(cuò)誤答案】【正確答案】易錯(cuò)