下面这段摘自《牛津英汉双解词典》电子版.
NOTE ON USAGE 用法:
Compare person,persons,people and peoples.
比较person、persons、people、peoples的用法.
1 People is the most usual plural of person.*people是person最通用的复数形式.Persons is formal and mostly used in legal language.*persons较文,主要作法律用语.
2 Person can also sound formal and is often avoided.*person有时也较文,通常避免使用.In general statements,the sentence can be made plural 在泛指时,此词在句中可用其复数形式:A person has the right to defend himself/People have the right to defend themselves.人人均有自卫权.When referring to a particular situation,we can say I saw someone/a man/a woman riding a horse instead of I saw a person riding a horse.在特指时,可以说‘我看见有个人[男的/女的]骑着马’（英文句中可以不用person,用someone/a man/a woman）.
3 People is also a singular noun (plural peoples) meaning `nation',`tribe' or `race' *people作‘民族’、‘部落’或‘种族’解时,是单数名词（复数是peoples）:The Ancient Egyptians were a fascinating people.古埃及人是个令人神往的民族.* the French-speaking peoples of the world 世界上说法语的民族.