person是可數名詞單數,復數可加s.people(人們)是一個集合名詞,說一個人不可用a people.因為它的意思是“一個民族”.比如：“教室里只有一個人”,要用person.即 There is only one person in the classroom.而“中華民族是一個勤勞勇敢的民族”,要用people,即"The Chinese people is a brave and hardworking people.