I'm talking to someone who is (or at least was) convinced that his English is
great. Someone who believes they have great proficiency already is never
going to get better.
Also, learning English is not easy. Not only is the entire way English
grammar works mostly alien to Asian languages (considering they developed
separately in isolation from each other for thousands of years), English also
inherits a whole lot of random stuff from Latin-based languages, which is yet
another branch.
I don't agree that negative feedback is detrimental to a really difficult
learning experience like this, and one major reason is my own personal
experience learning Japanese. When you underestimate the difficulty of a
language so much that you think you've almost mastered it, you never fix your
glaring inadequacies. My Japanese was atrocious last year. It was only when
someone had the guts to show me just how atrocious it was that I started to
get better.
I also don't think it is necessary for everyone to know English to be an
asset to the libre software movement, or any other cause. If he chooses to
abandon the English language entirely and focus on his own native language,
that's much better than wasting his and others' time using broken English.
This is a global movement and needs speakers from all languages.
