"Alfie?" Marcus shrugged. "He's never been good in classes, I guess? Like, even from first year Ellie's always been better at that stuff than him. But he's good in like... CoMC?" Which Marcus didn't really take much stock in. It wasn't that Alfie was dumb, he just wouldn't ever have been a Ravenclaw.
There might also have been a note of something else in his voice when he mentioned Ellie.