Translation:The boy eats, but he still feels hungry.
I did not, since I was unsure if it was actually correct or not. Not sure how to report from this screen though.
What is the difference between 'contudo' and 'mas'? Is one more common than the other?
I am going to argue that "but yet" is borderline grammatically incorrect. The primary use of the word in Modern English is as a coordinating conjunction (a conjunction that couples opposing ideas). This is also the primary function of but. Using them both together is redundant. However, in older modes of speech you could find "but yet" used so I cannot really say it's ungrammatical. "And yet" seems more natural too me as "and" is only a simple conjunction and is not used only to couple opposing ideas. http://grammar.ccc.commnet.edu/grammar/conjunctions.htm#yet