We use 인가 for several ways 1. to make a question (to say very casual form of asking, especially old generation saying ) 이게 자네 것인가? Is this yours? 이게 마지막인가? Is this the last? 2. to express feeling of a regret or something not good saying to oneself. 이제 끝이란 말인가? 정말 후회 되는군. Now, is this the end of it? 3. to make sure the fact saying to oneself. 이걸 여기다 끼우면 되는 것인가? So, should I put this into here, right?