Second Language Acquisition and the Critical Period Hypothesis

[sfuqua]

I learned Tagalog as an adult. I've been immersed in it for 31 years. I'm a B2 on a good day despite the input. There is more to it than just input.
Amusingly enough, I was asked by someone how to form the future tense in Tagalog a few months ago. I couldn't remember how to do it. I had to say a bunch of sentences and listen for the pattern before I could answer. So obviously, as an adult, I developed an unconscious system for forming the future in the language.

Just an anecdotal data point.

My wife is another data point. She was about an A2 in English when I met her, when she was 18. She had had formal classroom instruction in English. She was already a native speaker of Cebuano and a near native speaker of Tagalog. During the next few years, she worked as a waitress in English, dated an American (me), read a bunch of Stephen King, went to college and grad school in English, read a bunch of other novels, got a job teaching Math, and now is so close to a natives speaker that she can explain grammar points to our native speaker daughter. She writes and does presentations to native English speaker. She's been at this level for 25 years. But...

She occasionally messes up a vowel sound, which can lead to some hysterical mistakes which she usually can hear herself. Every now and then she butchers a preposition. She claims they make no sense, even though she almost always gets them right. It's been a few years, but she used to mix up he and she about once a month.

Some people can go all the way to near native speaker as an adult with some types of input, but without explicit study.

Despite how much this hurts me to say, nobody goes all the way to native speaker after puberty. Close, be not all the way.

Of course we need to specify what this means more explicitly. Perhaps something like the Turing test... Show me a person who learned a language after puberty who can fool a native speaker for a 20 minute interview. Even if we can find one, does one in a million mean that equivalent to native speaker is a reasonable goal?

[Senator Jack]

Highly enlightening anecdote, Sfuqua! Thanks for sharing. I wonder what it is about the brain that would just occasionally cause L1 transference/interference. On my to do list is research on the inner brain and animal communication systems. Are humans similar to animals in that we really are supposed to learn just ONE system (which may include multiple languages) before puberty? Perhaps we're really not wired to ever really supplant that system, but the cognitive mind tries to do it anyway.

Prepositions never seem to make any sense in any L2, do they?