I fear some of what we think we witness is actually in our heads. Meaningful vocal communication seems to be limited to such erudite topics as;
Wanting food.
Wanting to go out, come in, go out (etc)
Wanting affection.
Acknowledging affection (one of mine yips when you stroke her).
Warning off (the old hiss/yowl).
No, seriously (loud shriek)
Pain/fear (low meow - horrible to hear

)
Otherwise it mostly seems to be physical (ears, eyes, posture etc), or woo (imagined by doting baby-syndrome owners, made up by "facilitators" etc).
This seems pretty good gen, and
Cornell seem to have looked into it too.
ETA-
This is a breakdown of the identified noises in the repertoire.
As with even primates, there's no evidence of
language per se, but definitely some vocal communication (as any cat owner will tell you as per my own list above).