「この文章の文法はどうなっているの?」= What grammar are you using in that sentence? / What kind of grammar is used in that sentence? / What kind of grammar is that?
ボキャブラリー
grammar = 文法
using = 使っている
sentence = 文章
kind of grammar = 文型
相手に文法の使い方を説明して欲しいなら、こちらの文章を使えます:
Could you explain what grammar you used in that sentence?
I don't understand why you used that grammar. Could you explain?