> consistent practice with a fluent speaker where ones effort is being tested in some way like children
I agree with the total time and deliberate practice aspect but in my opinion you are underestimating one extra factor for adult learning.
As an adult if you practice a new language with natives (outside the context of a formal lessons) the majority of people will be a lot more accomodating of mistakes and mispronunciation simply because of the social pressure of wanting to 'save face' and not trying to demotivate the person who is learning.
There are maybe a handful of close friends who will be brutally honest enough to correct you, in the same way they would correct an infant. For the most part as an adult it is more common that you end up practicing with an 'excessively tolerant' feedback loop from other language natives.
I tried being “brutally honest” with an Indian coworker about her English. She started to studiously avoid me, and I realized I’d made a huge misstep following the “golden rule” so to speak. If I learn a new language I want people to constantly correct me.
I have another coworker who is Eastern European and she has explicitly told me “point out EVERY mistake I make. Be brutal, I want to learn perfect English.” So I do. It seems like she really is getting less of an accent from it. It’s pretty cool to see.
People are nice and don’t point out mistakes because some people don’t want this. It’s taboo on both sides, at least in the corporate US world. So they never learn to speak fluently just enough to get by.
I agree with the total time and deliberate practice aspect but in my opinion you are underestimating one extra factor for adult learning.
As an adult if you practice a new language with natives (outside the context of a formal lessons) the majority of people will be a lot more accomodating of mistakes and mispronunciation simply because of the social pressure of wanting to 'save face' and not trying to demotivate the person who is learning.
There are maybe a handful of close friends who will be brutally honest enough to correct you, in the same way they would correct an infant. For the most part as an adult it is more common that you end up practicing with an 'excessively tolerant' feedback loop from other language natives.