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        高考英語復習:數(shù)詞用法

        字號:

        高考英語復習:數(shù)詞用法
            天津四中 李好
            在學完定語從句之后,同學們會接觸到的另一個語法項目是數(shù)詞。表示數(shù)目、多少和順序先后的詞叫數(shù)詞。數(shù)詞有兩種:表示數(shù)目多少的數(shù)詞叫基數(shù)詞,如:one,ten twenty-three;表示順序先后的數(shù)詞叫序數(shù)詞,如:first,third,twentieth。
            1.基數(shù)詞
            基數(shù)詞相當于名詞,在句中可做主語、表語、定語、狀語等。如:
            Three of my classmates are from Shanghai.
            I am twenty this year.
            They have four classes in the morning and three in the afternoon.
            2.序數(shù)詞
            1)序數(shù)詞的構成:
            ★大多數(shù)的序數(shù)詞是由基數(shù)詞加-th構成。如:seven—seventh;ten—tenth
            ★以-t結尾的基數(shù)詞只在詞尾加-h。如:eight—eighth
            ★以-ve結尾的基數(shù)詞改-ve為f再加-th。如:five—fifth;twelve—twelfth
            ★以-y結尾的基數(shù)詞改-y為-ie再加-th。如:twenty—twentieth,thirty—thirtieth
            ★幾十幾的序數(shù)詞只在個位數(shù)體現(xiàn)。如:twenty-one—twenty-first;thirty-three—thirty-third
            ★特殊的序數(shù)詞:
            one—first;two—second;three—third; nine—ninth
            2)序數(shù)詞在句中同樣可做主語、表語、定語、狀語等。如:
            June the first is Children’s Day.
            When did you first meet each other?
            She was the last to arrive.
            3.數(shù)詞的用法:
            1)表示年、月、日,“年”用基數(shù)詞,“日”用序數(shù)詞。如:May eleventh,2007
            2)表示時間。如: It’s eleven twenty.
            3)表示編號。編號既可以用基數(shù)詞表示,也可以用序數(shù)詞表示。區(qū)別是基數(shù)詞用在名詞之后,序數(shù)詞位于名詞之前,并加定冠詞。如:Lesson Nine;the Ninth Lesson
            4)介詞 in one’s+整數(shù)數(shù)詞的復數(shù)形式,表示年齡。如:
            She is in her early forties.(她四十出頭。)
            5)序數(shù)詞前加冠詞“a”表示“再一次”。如:Can I try a second time?
            6)在hundred,thousand,million,billion前有數(shù)詞時為實數(shù)意義,它們的詞尾不能加復數(shù)。前無數(shù)詞時為虛數(shù)意義,hundred,thousand,million,billion可加復數(shù),并可和of連用,構成短語。如:five hundred students;millions of people
            4.分數(shù)的構成
            分子用基數(shù)詞,分母用序數(shù)詞,分子大于1時,分母加s,如:
            1/5:one fifth
            2/3:two thirds
            2-:two and three quarters
            5.小數(shù)的表示法
            0.09:point zero nine
            2.7:two point seven
            6.百分數(shù)的表達法
            90%:ninety percent
            0.5%:point five percent
            7.倍數(shù)表達法
            表示兩倍時用twice,表示三倍以上的倍數(shù)時用times。如:
            The earth is 49 times the size of the moon.
            This desk is twice as large as that one.
            8.算式表達法:
            5+6:five plus six(or five and six)
            7-6:seven minus six
            2×3:two multiplied by three(or two times three)
            8/4:eight divided by four
            9.與數(shù)詞相關的主謂一致原則
            1)當名詞詞組中心詞為表示時間、路程、金錢或重量等復數(shù)名詞時,往往根據(jù)意義一致的原則,把這些復數(shù)名詞看做一個整體,謂語采用單數(shù)形式。如:
            Twenty dollars is not enough.
            Two months has passed before we realized.
            但是如果“數(shù)詞”單用,表示人或物,謂語動詞一般用復數(shù)。如:
            Three were killed and ten were missing in that accident.
            2)如果名詞詞組中心詞是“分數(shù)或百分數(shù)+of-詞組”,謂語動詞的單、復數(shù)形式取決于of-詞組中名詞或代詞的單、復數(shù)形式:如果of-詞組中名詞或代詞是單數(shù)或不可數(shù)名詞,謂語動詞用單數(shù)形式;如果of-詞組中名詞或代詞是復數(shù),謂語動詞也用復數(shù)形式。如:
            Two thirds of the earth is covered with water.
            Two thirds of the people present are against the plan.
            3)如果主語是many a,more than one+單數(shù)名詞構成,盡管從意義上看是復數(shù),但謂語動詞仍用單數(shù)形式。如:
            Many a student in this class has hoped a long break.
            4)a+單數(shù)名詞+or two做主語,謂語動詞用單數(shù)形式。如one or two+復數(shù)名詞,謂語動詞用復數(shù)形式。如:
            A word or two is missed in the sentence.
            One or two words are missed in the sentence.