Semi-nerdy zombie knowledge-ENGAGE!!
Ok so first of all, zombies don't actually ever stop being hungry, there is never enough for a zombie, the thing about them eating until their stomachs burst isn't just sarcasm (or whatever).
Two, them being undead is good enough reason to not have sufficient intellect to hold a conversation, mainly because there is no intellect to speak of. The zombie mind is capable of two things, identifying its own basic instincts, and acting on them. This includes feeding, and nothing else. There is no strategy involved in zombie outbreaks, at least not for the opposition, there is only human (or...well, live being) stupidity.
Three, even if sufficient intellect was available, the being in question would still be completely unable to form words, sentences, etc. This is because the being's vocal cords and such would be rendered useless due to decomposition.
There are a few holes in the question, as well as some of the responses, but it's an interesting question all the same.
/nerdy zombie rant