育才学习网1.1到30的序数词英文怎么写
首先搞清楚基数词和序数词，
基数词，表示数量，1,2,3，表示多少个
序数词，表示顺序，第1，第2，第3，表示第几个
1-30的序数词，前3个是特殊情况，需要单独记忆，从4开始往后，基本上都是在基数词的词根后面加th，但是词根变化较多，尤其结尾部分，要注意。
还有，所有序数词之前，都要加the。
1-10,first, second, third,fourth,fifth,sixth,seventh,eighth,ninth,tenth
11-20,eleventh,twelfth,thirteenth,fourteenth,fifteenth,sixteenth,seventeenth,eighteenth,nineteenth,twentieth
21-30,twenty first, twenty second,twenty third,twenty-fourth,twenty-fifth,twenth-sixth, twenty-seventh,twenty-eighth,twenty-ninth,thirtieth
2.1~90的英文序数词怎么写
1到20为：
first、second、third、fourth、fifth、sixth、seventh、eighth、ninth、tenth、eleventh、twelfth、thirteenth、fourteenth、fifteenth、sixteenth、seventeenth、eighteenth、nineteenth、twentieth
21到40为：
twenty-first、twenty-second、twenty-third、twenty-fourth、twenty-fifth、twenty-sixth、twenty-seventh、twenty-eighth、twenty-ninth、thirtieth、thirty-first、thirty-second
thirty-third、thirty-fourth、thirty-fifth、thirty-sixth、thirty-seventh、thirty-eighth、thirty-ninth、fortieth
41到60为：
forty-first、forty-second、forty-third、forty-fourth、forty-fifth、forty-sixth、forty-seventh、forty-eighth、forty-ninth、fiftieth、fifty-first、fifty-second、fifty-third、fifty-fourth、fifty-fifth、fifty-sixth、fifty-seventh、fifty-eighth、fifty-ninth、sixtieth
61到80为：
sixty-first、sixty-second、sixty-third、sixty-fourth、sixty-fifth、sixty-sixth、sixty-seventh、sixty-eighth、sixty-ninth、seventieth、seventy-first、seventy-second、seventy-third
seventy-fourth、seventy-fifth、seventy-sixth、seventy-seventh、seventy-eighth、seventy-ninth、eightieth
81到99为：
eighty-first、eighty-second、eighty-third、eighty-fourth、eighty-fifth、eighty-sixth、eighty-seventh、eighty-eighth、eighty-ninth、ninetieth、ninety-first、ninety-second
ninety-third、ninety-fourth、ninety-fifth、ninety-sixth、ninety-seventh、ninety-eighth、ninety-ninth
扩展资料
在英语中，使用序数词时前面要加定冠词 the，但是，在下面的情况下则不加 the:
1.当序数词前有形容词性物主代词或名词所有格修饰时，序数词前不用 the。
例句：Mother was my first teacher in my life.妈妈是我生命中的第一个老师。
2.当表达分数时，序数词前不用 the。
例句：One fifth of the students here are from the country. 这儿1/5的学生来自农村。
序数词变化规则口诀：
1.基变序，有规律，词尾加上-th.
2.一，二，三，特殊记，词尾字母t,d,d.
3.八去t，九除e,ve要用f替，ty将y变成i,th前面有个e.
4.若是碰到几十几，前用基来后用序.
5.整十基数变序数，先把ty变成tie.
6.要是遇上2位数，十位基数，个位序，th最后加上去.