I have to hand it to the professor... That's a lot of work. I correct English on a language exchange site for fun. But it doesn't take long before I start to

I have to hand it to the professor... That's a lot of work. I correct English on a language exchange site for fun. But it doesn't take long before I start to look at it as a chore, and not much fun. He does it for a living, all day, and comes back for more!