I have three cats. Cutie and Lydia are sisters, and they are twenty-four years old. Ella is just over a year old.
Although I have read in several books that cats meow as a way of communicating with people, not one another, Lydia calls for Ella all the time. For some reason, once she accepted Ella into the house, she wants to have her by her side whenever she's not in one of her cat beds. On her part, Ella dutifully comes running more often than not. I don't know what it's about because they seldom play. Rather, they simply walk around the house together. Lydia never speaks to me. She loves to be petted and to be brushed, but only when she is in one of her safe zones, these being her cat beds or the cat tree. Lydia has always been a flake.
Cutie meows to get my attention when I am working on the computer or not otherwise noticing her. Once she has my attention, she communicates in other ways. She has her own cardboard box, which no other cat is allowed to set foot in, let alone lie down in, and she loves it when I pick up her box while she's in it, and fly her around the room, lift her up to the ceiling, drag her across the floor, or simply set her box on my lap while she's in it. I call that box time and once she gets my attention, if I reach down to pet her she will retreat to her box, which is her way of telling me that she wants box time. For about a year, she had a tradition of bringing me a toy, which she used purely as a prop, as a way of signaling the need for box time. At time, there was only enough time between box times for her to find another toy and bring it to me. Otherwise, if she's hungry, she will meow in the same way, to get my attention, then retreat to her feeding station. She might want me to lie down in the bed with her, and will lead me upstairs to the bed as a way of conveying that message. Basically, the meow is to get my attention, and the rest of it is a matter of leading me to whatever it is that she wants. There are also times when she gets my attention for reasons that I am unable to determine.
Being young, I haven't quite figured Ella out yet. When she doesn't like a particular type of cat food, she will make digging motions alongside the bowl, as if to cover it up, before walking away. She also inspects each litter box as I am cleaning it, and will let me know if she doesn't think it's clean enough. Being twenty-four, Lydia sometimes has "accidents" outside of the litter box, and Ella will tell on her. Other things are harder to tell. She will often check in with me by putting her paws on my knee, sinking her claws in just enough to get my attention. That seems to simply be a way of saying hello as she's passing through.
She has a bad habit of scratching on door posts. Yesterday, when she did that, I said, "Ella, quit tearing my house apart." She stopped and looked at me, then walked over to one of the legitimate cat scratchers that we have in the house, put her paws on it, and looked at me, as if to say, "Can I scratch here?" Then she went to the sisal rope on the cat tree and did the same thing. That was quite impressive, except that a few minutes later, she was scratching on the door post again.
I have always had cats, and they do seem to make an effort to communicate. Some are better at it than others, but I'm not always so good at listening either.