Grown cats rarely, if ever, meow at one another.  As kittens, cats meow to ask things of their mothers – so if your grown cat talks to you, it may be an indication that he or she sees you as a maternal figure. According to Catster, “A cat reaches the approximate human age of 15 during its first year, then 24 at age 2. Each year thereafter, it ages approximately four ‘cat years’ for every calendar year. Thus, a 5-year-old feline would be approximately 36 in cat years.z” Source: Trupanion