My cats are both bilingual - well, make that trilingual. However, their listening - in English and Japanese - far exceeds their speaking.
Probably the first word they learned was “No!” They quickly understood that “no” meant stopping whatever they were doing. If I say, “Watch out” or “Abunai,” they're a bit more confused by what to do or not to do, so there's still a bit of learning to take place there.
Occasionally I'll teach them some big words, such as “rambunctious” (when I was explaining their behavior to them). However, those words don't stick as well.
Their favorite word is “din din,” which stands not just for “dinner” but for any meal. Just hearing “din din” is enough to get them excited, and they immediately head for their bowls in the kitchen.
Recently Tippy's speaking has gotten almost as good as his listening. (I can't say the same for Mac, who has only 2 sounds in his vocabulary - a whine or a bark, the latter saved for crows outside the window.)
Quite some time ago, Tippy could say “Ma” when he saw me. Now he's added 2 more words. He was pushing against the handle of the front door the other day (and probably would have opened it if it hadn't been locked). I asked him where he was going, and he replied, “Out.” Later I asked him when he wanted his “din din,” and he replied, “Now.”
It could be he's so literate because, nearly every night when I'm reading before going to sleep, he comes over to my futon for his bedtime story. He likes to curl up on my tummy, with his butt in my face, so he can look at the book - even though it has no pictures. Of course, my stroking him may have something to do with his enjoying reading with me. If I read more material in Japanese, I wonder if Tippy's spoken Japanese would get better.
Into summer mode.... - We survived. Okaasan and Me and Knee - all week. The cooking wasn't very creative. She ate prepared food boxes for 3 days while I worked long hours. But sh...
3 hours ago