文档介绍：英语基数词变序数词口诀基变序,有规律,词尾加上-th。一,二,三,特殊记,词尾字母t,d,d。八去t,九除e,ve要用f替,ty将y变成i,th前面有个e。若是碰到几十几,前用基来后用序。整十基数变序数,先把ty变成tie,要是遇上两位数,十位基数,个位序,th最后加上去。一,二,三变字体;th从4上起;8加h,9减e;用f代ve;ty变为tie。解析口诀:one→first,two→second,three→third这三个词变化特殊,要单独记;eight→eighth,nine→ninth,八去t,九去e后再加-th;five→fifth,twelve→twelfth,五、十二把ve换成f再加-th;twenty→twentieth,thirty→thirtieth...整十先把词尾y改为ie再加-th。两位数时则十位数用基数词,个位数用序数词,如:twenty-first。eenth19th第20twentieth20th第21twenty-first21st第22twenty-second22nd第23twenty-third23rd第24twenty-fourth24th第25twenty-fifth25th第26twenty-sixth26th第27twenty-seventh27th第28twenty-eighth28th第29twenty-ninth29th第30thirtieth30th第31thirty-first31st第32thirty-second32nd第33thirty-third33rd第34thirty-fourth34th第35thirty-fifth35th第36thirty-sixth36th第37thirty-seventh37th第38thirty-eighth38th第39thirty-ninth39th第40fortieth40th第41forty-first41st第42forty-second42nd第43forty-third43rd第44forty-fourth44th第45forty-fifth45th第46forty-sixth46th第47forty-seventh47th第48forty-eighth48th第49forty-ninth49th第50fiftieth50th第51fifty-first51st第52fifty-second52nd第53fifty-third53rd第54fifty-fourth54th第55fifty-fifth55th第56fifty-sixth56th第57fifty-seventh57th第58fifty-eighth58th第59fifty-ninth59th第60sixtieth60th第61sixty-first61st第62sixty-second62nd第63sixty-third63rd第64sixty-fourth