英语人教版八年级上册序数词.doc

序数词的用法1. 序数词前要加定冠词the, 通常放在名词前面作定语。例如:The second lesson is more difficult than the first. 第2课比第1课要难。2. 给东西或各种物体编号时,序号在前时用序数词,序号在后时用基数词。例如:the Fifth Lesson, Lesson Five, No. 14 Middle School3. 序数词前面加不定冠词a/an, 表示“再一”、“又一”的意思。例如:Try it a second time. 请再试一次。He cast it a third time, and drew in a lot of stones. 他又撒了第三次网,拉上来许多石头。【练一练】 写出与下列基数词相应的序数词。1. one_ 2. two_ 3. three_4. four_ 5. five_ 6. eight_7. nine_ 8. ten_ 9. twelve_10. twenty_ 11. thirty-one_ 12. sixty-five_Key:1. first2. second3. third4. fourth5. fifth6. eighth7. ninth8. tenth9. twelfth10. twentieth11. thirty-first12. sixty-fifth序数词的构成方法1. 一般在相应的基数词后面加词尾-th。 例如:fourfourth, sixsixth, sevenseventh, tententh, eleveneleventh, thirteenthirteenth注意下面的一些特殊变化: onefirst, twosecond, threethird, fivefifth, twelvetwelfth,eighteighth, nineninth2. 表示“几十几”或“几百零几”的基数词变为序数词时,只将个位数变为序数词,十位数或百位数不变。例如:twenty-onetwenty-first, thirty-threethirty-third, forty-fourforty-fourth3. 以-ty结尾的基数词变为序数词时,应先将y改为i, 再加-eth。 例如:twentytwentieth, thirtythirtieth, fortyfortieth, fiftyfiftieth, sixtysixtieth, seventyseventieth, eightyeightieth, ninetyninetieth4. 序数词的缩略式一般由阿拉伯数字加上序数词的最后两个字母构成。例如:first1st, second2nd, third3rd, fourth4th, twelfth12th, twenty-first21st基数词变序数词口诀:基变序,有规律, first, second, third要牢记;其余变化有规律,基数词尾加-th; eight去t、 nine去e后加-th。从twenty, thirty到ninety, 需先变y为ie, 再加-th;five和twelve, 需将ve变f, 然后再加-th。若要变成“第几十几”,只变个位就可以。1.定冠词的用法归纳总结2.数词的用法归纳3.定冠