I'm curious to know what sort of grammatical mistakes are made by native German speakers. Are there errors in speech or writing that give a native away as being poorly educated?
Native English speakers often confuse to/too/two, their/they're/there, or use incorrect (but correct-sounding) constructions like ”for she and I”. I’m assuming that the mechanics of the German language make these sorts of mistakes less common. Do less-educated Germans get noun genders wrong? Or confuse accusative and dative prepositions?
My question is explicitly about recognizable errors, not colloquialisms, dialects, or informal speech patterns.