YOU SAID:

My boyfriend does not understand the concept of this game.

INTO JAPANESE

私のボーイフレンドはこのゲームの概念を理解していません。

BACK INTO ENGLISH

My boyfriend doesn't understand the concept of this game.

INTO JAPANESE

私のボーイフレンドはこのゲームのコンセプトを理解していません。

BACK INTO ENGLISH

My boyfriend doesn't understand the concept of this game.