I stamp this!
As a receptive bilingual who's just moved out to Ghana, I've quickly realized merely being exposed to the language hasn't changed my ability to express myself in it (the language is Akan Twi).
I've recently started seeing progress when I started learning the phonetics of different letters and how various words sound when they come together.
The biggest difficulty is learning not to switch back to English when reading a word, which is pretty hard since the letters (most) look the exact same.
Great post Mathias!