一,自己找
1st = first
2nd = second
3rd=third
4th=fourth
5th=fifth
6th=sixth
7th=seventh
8th=eighth
9th=ninth
10th=tenth
11th=eleventh
12th=twelfth
13th=thirteenth
14th=fourteenth
15th=fifteenth
16th=sixteenth
17th=seventeenth
18th=eighteenth
19th=nineteenth
20th=twentieth
21st=twenty-first
22nd=twenty-second
23rd=twenty-third
24th=twenty-fourth
25th=twenty-fifth
26th=twenty-sixth
27th=twenty-seventh
28th=twenty-eighth
29th=twenty-ninth
30th=thirtieth
表示顺序的数词称为序数词.
序数词的构成：
1、序数词一般由基数词在词尾加-th构成.
如：ten-tenth six-sixth
2、以ty结尾的基数词要先把y为i、再加-eth.
如：thirty-thirtieth seventy-seventieth
3、20以上的十位或百位的基数词、只将其个位上的基数词变为序数词就可以了.
如：forty-three—forty-third sixty-eight—sixty-eighth
4、序数词有时用缩写形式.
如：first-1st second-2nd third-3rd ninrty-second—92nd