a) Grama ochie nwere usoro na iwu na-achị ya (normative), ma kwuo etu a ga na-eme asụsụ (prescriptive), kama ọ ga-akọwa etu e si eji ya eme ihe (descriptive), nakwa ịkọwa nke ọma etu e si were asụsụ mee ihe (explicit).
