Communication and a few of its definitions:
-able to converse in any language
-able to explain anything in particular
*vital for teaching

If Song was capable of this, then i wouldnt be writing this review. But wait, it cant be that bad right? YES IT CAN!! I went to his office hour and could not understand him. HE WAS SITTING RIGHT NEXT TO ME!! I asked him for help and he made sounds using his vocal cords and just TOOK my paper and TOOK my pencil and just started doing the problem. And DIDNT finish. If you are good at math dont go to class (just read the book IT IS THE SAME, if not BETTER, because the book is able to freaking COMMUNICATE!!!). If not I suggest Brown, a very caring professor who CARES ABOUT TEACHING.
Something else to think about- how in the heck did Song not get denied during his interview? I mean i wouldnt hire someone who is unable to hold a conversation? Anyway I thought 31b was a particularly hard class and it would be nice if i had an instructor LIKE I SHOULD HAVE HAD.

His accent makes it impossible to understand and if you are slightly not interested in the subject or a little sleepy, there's no way you can stay awake in th class!