I can't speak to formal writing style in Swdesh or German, but as an Anglophone Dyslexic I can tel you that there is a difference between the way Dyslexics write, stylistically, compared to non Dyslexics. We tend to punctuate for rhythm rather than meaning, and we produce constructions which mirror our vocal patterns, rather than written grammar.
Put another way, Dyslexics don't learn to write so much as they learn to transcribe speech.
Dyslexics tend to make good playwrites, poets, actors, and to lesser extend novelists for this reason.
The bad at leaning foreign languages is a new one on me, and makes little sense, unless you mean writing or reading a foreign language, which is separate from learning one.
Bookmarks