a person和one person哪个用于句子比较好

您能不能给我们例句?

(1) "one person" 很少用,因为"one"有"one person"的意思:

(a) One cannot help but grow older.

(b) If one were to fail,that would be unfortunate.

(2) 除非是人家问你：How many (persons)?你才答:One; one person.

(3) "a person" = My brother is a person who is very hardworking.一个勤奋的人

也可以这样写:My brother is one who works very hard.