endgame with basic checkmates


Learning checkmating patterns is a very vital skill in chess. When I was about 300 or so I tried explaining what a checkmate is to my opponent, I tried putting an example of what a checkmate is but it turns out I also did not know what I am explaining. When you play a winning endgame with just a rook and your opponent's king, your opponent will hope you don't know how to checkmate with the rook, if you do not know how to checkmate with the pieces you have you will not know how to win your game. You will perhaps accidentally stalemate or draw by insufficient material.
To answer your questions here are my answers:
1. Yes
2. Yes and no, depending on the position
3. Yes, as it teaches you fundamentally the correct way of what to do with your opponent's threat or what to do when you have an advantage containing checkmates similar to what basic checkmates you learned, even if your opponents resign.