Why can't Ozzy Osbourne talk but he can sing?

Answer

Why can Ozzy sing, but not talk? Well, it's because he already knows what he's going to say before he says it!

Actually; the Oz can talk but he has such a Brummie accent that he is almost non-distinguishable from a mumble, but if you pay attention to him you can hear and understand him. Not to mention the 30+ years of booz and drugs didn't help things for him. God bless Sharon for being by his side throught he years or he may have ended up like Morison and Hendrix

-While Ozzy may have an accent I don't think that is why people cant understand him. I'm pretty sure that the majority of his speech problems stem directly from heavy and prolonged use of drugs and alcohol. He should be the anti- drug poster child. That being said Ozzy still rocks.

No; I've heard interviews from his days in Sabbath, and he sounds almost exactly the same. It's mainly the accent, I think, and also the overall tone of his voice.