yes, trying to understand cat and dog communications is half the fun of having them as companions. both of my cats have meows i can understand by sound and context, whether it's hunger, attention-seeking, calling for help, etc., but each has individual tendencies. for instance, my older one uses short fast meows to wake me up to feed him, while the 9-month-old meows her disappointment when i disrupt her play by picking her up. she also tries to talk to me, watching me with her curious eyes to see if i understand her. =)
One of my cats understood a small vocabulary. I first noticed it when I mentioned "catnip" in a sentence and she got excited. She learned a number of words during her life, mostly - but not all - food related. She had no problem picking them out of a sentence, so we learned to avoid saying certain words when not appropriate.
