That’s all covered by “non-standard” - because the standard of a language dictates what’s to be taken as informal/vulgar/archaic, dialectal, slang, different words or the same word, etc. And while there are exceptions most of the time when people learn a non-native language they learn the standard, in detriment of other varieties.
(Sorry for nerding out about this, I just love this sort of topic.)
That’s all covered by “non-standard” - because the standard of a language dictates what’s to be taken as informal/vulgar/archaic, dialectal, slang, different words or the same word, etc. And while there are exceptions most of the time when people learn a non-native language they learn the standard, in detriment of other varieties.
(Sorry for nerding out about this, I just love this sort of topic.)