跟他談一談，

去租一些電視連續劇  like  "Roots" , or movie like 'Hidden Figure',  "Roots"  is about slavery in America, 'Hidden Figure' how african Americans fought for equality in the 50s and 60s .

N-word is the most hated word by African Americans, so unless he wants to get expelled from school, don't ever use that word again.