eleven十一
twelve十二
thirteen十三
fourteen十四
fifteen十五
sixteen十六
seventeen十七
eighteen十八
nineteen十九
twenty二十
eleventh(11th)第十一
twelfth(12th)第十二
thirteenth(13th)第十三
fourteenth(14th)第十四
fifteenth(15th)第十五
sixteenth(16th)第十六
seventeenth(17th)第十七
eighteenth(18th)第十八
nineteenth(19th)第十九
twentieth(20th)第二十