Very good article but something bothers me:

> Language learners chase something called i+1 material

I really dislike the traditional language teaching method. It didn't work for me. It's too abstract, boring, and you end up memorizing stuff the wrong way. And usually later you need to un-learn/re-learn things properly.

What worked for me (and fellow struggling students I taught) was normal text about topics I find interesting. Like boats? Pick boating magazines, books, and documentaries/movies (turn subtitles on). From WTF to "I know some of those words" to is that a pattern? And only then go for the actual rules of the language. This way you are engaged and learn real-world things.

And for dull learning, it's better to spend time in i-1. Miyagi-stile practice repetition of the basic things to the point you can't fail even if you are tired. Then move to games like finding rhymes or tongue-twisters. [Ironically, AFAIK this is the Japanese way to learn calligraphy, Judo, etc]

Same applies to many other disciplines. YMMV