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.
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.
One fifth of the students here are from thecountry.这儿1/5的学生来自农村.
3.当表达“又一,再一”时 ,序数词前不用 the,但可加不定冠词. Please give me a second chance.请再给我一次机会.
4.当表达“年月日”时,尤其在朗读时,序数词前要加the;但当书写时,序数词前不用the.He was born on June 6th,1974.他出生在1974年6月6日.
5.当序数词在句中作状语时,序数词前不用 the.
Who got there second?谁第二个到那儿的?
6.当表达考试(赛跑等)中获得的名次时,序数词前不用 the. She stands first in her class.她在班上成绩排名第一.
7.当用在一些习语中,序数词前不用 the. First come,first served.捷足先登/先到者优先. at first sight 乍一看到 first and last 总计,一共 first of all 首先