In their own language, yes.
My cat communicates very well. She can tell me off if her food bowl is empty or if it's too hot or if I haven't been paying attention to her. I can tell the difference. When I wake up in the morning she is often right there and I know exactly what she is saying.<br />
Sometimes when we are playing we have conversations where I will say "Yow" and she will say "Yow" back, then I say "Yeow" and she repeats it, then "Yeee-ooow" and so on. We both know we aren't really saying anything, but it's more like a conversation than I've had with a lot of girlfriends!
Mine can. He can so "no," "now," "I," "low," and "Joe."<br />
Not that he knows what any of those mean, but sometimes it sounds like he's imitating humans.
Last time I checked… no.