history: My brother is a math wizard. I was taking a math class that I found really tough. He tutored me through the whole semester and I got a great final grade. I really appreciate his efforts! My brother is really great at math. When I was taking a really hard math course he was so happy to help me throughout it and I did great in the class thanks to him! You must have thanked him for it. He is a smart brother!
current: I did thank him a lot. He knows how much it meant to me.
next: Good on you. Your brother should consider being a teacher! 