This makes sense. I have fairly good L2 German production, but I go from conversant to barely coherent when fatigued. My L1 English production diminishes, but not nearly as much. Likewise, my friends who speak English as an L2, even those who have spoken it with a strong command for over a decade, will struggle when very tired. Though we usually speak in English (her English is way better than my German), I've had a…
Regarding the follow-up... I grew up speaking only Russian. I moved to the US when I was 15. I had 7 years of deliberate English practice prior to the move and became fluid in it within a year of moving. That was about 30 years ago. Because I moved alone, and didn't seek out Russian speakers for this 30 year duration, I only occasionally spoke Russian. The result is that now my Russian feels like a second language. W…
I didn't know you could 'lose' a native language that you grew up with til near adulthood. Maybe speaking has more to do with muscle memory and hence easier to lose than a somewhat passive skill like listening and comprehension. Makes me wonder how language is stored and processed in the brain. Are there two complete separate regions for speaking and listening? That feels a bit inefficient.