Actually, they are using slang...saying "I thought you...I thought..."..."You thought it was easy but it's not!" Just so you know, this is a bad example of English because they aren't really using correct grammar or even pronunciation. They are speaking in half-sentences so it is hard to follow what they are saying...don't worry too much if you don't understand that part because it doesn't really have anything to do with the song... Hope this helps...email me of you need more explanation.. ^^;;

I taught You taught it was easy but it was hard

A:" i told you already" C:" you told is easy,but...t***" (t*** i have no idea what's that?)