Oddly enough I think some kinds of foreign learners end up _more_ worried about some aspects of written english than native speakers. Things like they're/there/their, affect/effect, it's/its etc are more likely to deceive someone who learned english orally than someone who did it by the web/as a second language.
At least, as a foreigner, it never ceases to amaze me that these things are even issues at all.
I think it might have something to do with translating. These "confusing" sets of words are translated as completely different things in portuguese. On the other hand, my high school teacher usually used "why" and "because" to explain the difference between "porque" and "por que" in portuguese (and she could, although she didn't, also use "the reason" as an analogy for "o porquê").
> Foreign learners shouldn't worry about proper English the way native speakers do.
Why not? Positive action? As a foreign learner, I don't want to be judged by lower standards. That would label me as "the French man"[1]. That would be a form of exclusion. That would lose me credibility.
Moreover, I am not judged by lower standards. In most contexts, people don't even know that I'm not native. They will judge me by natives' standards like I do you.
The catch is, I am not a native speaker. So, the only way to catch up is to worry more than native speakers. So I should. So I do.
[1] I once was told that unlike the Merovingian, Lambert seldom have a French accent, if at all. That he was upset when he was asked to fake it.
Good is good enough. I understand what he means.
Foreign learners shouldn't worry about proper English the way native speakers do.