Musings from my inner linguist

It feels sudden, but I guess it's been a year in the making: we now have a talker.
I swear last week William didn't say any words, and then now he says a good handful.
It has been sudden.
More than the girls, William has been babbling lots of sounds with lots of inflections and intonations. He'll carry on full babbling conversations with his sisters in the back of the car, and sometimes he'll just jabber to himself. It's pretty much the cutest thing in the world.
Now he says a few words.
First word: "Bye"
He has been saying a general "ah" as both "hi" and "bye" for some time, but when it finally became a word it was definitely "bye" and used solely when he or someone else was leaving.
Other words: mama (yay!), uh-oh, zai jian (from the end of one of his sisters' Chinese songs), Dad, and something that sounded remarkably like "I love you," especially through my filter of wishful thinking.

I took a few linguistics classes in college (okay, so I took one twice...), and I would find myself getting caught up in reading the textbooks. I think languages are fascinating, especially language acquisition in children and foreign language acquisition.
I was always fascinated by the idea of learning a different language. I'd hear from missionaries returned from various lands, forgetting words in English or trying to explain a foreign phrase. I imagined that when you learned a second language, those words would sound in your head like your native language. Like if someone said ni hao ma to me, then after I learned Chinese, it would sound to me like someone said, how are you.
That's not quite how it works.
When someone asks you, "What's up?" you don't look at the ceiling and wonder what IS up. No, you've already learned and filed that phrase away in the category of Greetings, more specifically, Greetings from People Trying to Sound Casual and Hip.
So when I learn a foreign language, ni hao ma just gets added to the Greetings category in my mind, but it's in a separate category of Greetings from People Whom I Should Respond to in Chinese. The Chinese word doesn't "replace" an English greeting or even sound the same in my head, but it fits in the same category, in its own space.
Really, we're all learning a second language. That is, we're learning more and more language every day, and we have several layers of language building up all the time. People start hearing "I know, right?!" or "I. Just. Can't. Even." so often that they start using the phrases themselves. Even old people know what a "selfie" is. We're adding on to our own language, often adding words and phrases that we already have a name for (self portrait, picture of myself). Basically, we're padding our native language until it's a huge mountain of words. When we learn a second language, we start a new little anthill of language. We know where all the empty spaces are, and it's a little tedious and overwhelming to have to fill each one grain by grain, but it's fun once you have enough grains of sand to start.