Yeah, he's had problems with his knee for aaaages. :|
Haha, I need to tell you a funny story: I have this little brother, who's 4. I teach him a bit of Spanish every now and then, because he likes speaking Spanish and telling people that he can speak Spanish xD Anyways, he was at Target with my dad and he told the cashier girl that he could speak Spanish. When they were leaving, the cashier said to him, "Adios, amigo!" My brother replied: "Si," which means 'yes'. xD