數詞有基數詞和序數詞兩大類。小編整理了數詞的語法基礎知識介紹,歡迎欣賞與借鑑。
基數詞
(1)1-20
one,two,three,four,five,six,seven,eight,nine,ten,eleven,twelve,thirteen,fourteen,fifteen, sixteen,seventeen,eighteen,nineteen,twenty
(2)21-99 先說“幾十”,再說“幾”,中間加連字元。
23→twenty-three,34→thirty-four,45→forty—five,56→fifty-six,67→sixty-seven,78→seventy-eight,89→eighty-nine,91→ninety-one
(3)101—999先說“幾百”,再加and,再加末兩位數或末位數;
586→five hundred and eighty-six,803→eight hundred and three
(4)l,000以上,先從右往左數,每三位數加一個“,”,第一個“,”前為thousand.第二個“,”前為million,第三個“,”前為billion
1,001→one thousand and one
18,423→eighteen thousand,four hundred and twenty-three
6,260,309→six million two hundred and sixty thousand three hundred and nine
750,000,000,000→seven hundred and fifty billion
序數詞
(1)一般在基數詞後加th
→fourth,thirteen→thirteenth
(2)不規則變化
one→first,two→second,three→third,five→fifth,eight→eighth,nine→ninth,twelve—twelfth
(3)以y結尾的.十位整數,變y為ie再加th
twenty→twentieth, forty→fortieth, ninety→ninetieth
(4)從二十一後的“幾十幾”直至“幾百幾十幾”或“幾千幾百幾十幾”只將個位的基數詞變為序數詞。
twenty-first,two hundred and forty-fifth
基數詞轉為序數詞的口訣:
基變序,有規律,詞尾加上-th.
一,二,三,特殊記,詞尾字母t,d,d.
八去t,九去e, ve要用f替。
ty將y變成i,th前面有個e.
若是碰到幾十幾,前用基來後用序。
數詞的用法
1)倍數表示法
a. 主語+謂語+倍數(或分數)+ as + adj. + as
i have three times as many as you.我有你三倍那麼多。
b. 主語+謂語+倍數(分數)+ the size (amount,length…) of…
the earth is 49 times the size of the moon.地球是月球的49倍。
c. 主語+謂語+倍數(分數)+ 形容詞(副詞)比較級+ than…
the grain output is 8 percent higher this year than that of last year.
今年比去年糧食產量增加8%。
d. 還可以用by+倍數,表示增加多少倍
the production of grain has been increased by four times this year.
今年糧食產量增加了4倍。
2)分數表示法
構成:基數詞代表分子,序數詞代表分母。分子大於1時,分子的序數詞用單數,分母序數詞用複數:
1/3 one-third ; 3/37 three and three-sevenths.