Sprachandragogik; Volkshochschule; Adult language teaching ; UG; Universal grammar ; Learnability (of language) ; Lernbarkeit (von Sprache) ; Spracherwerb (Theorie) ; Language acquisition (theory of) ; Poverty of the stimulus-argument; Theory (language acquisition) ; Second language acquisition (psycholing.) ; Case study (second language acquisition) ; Transfer (second language acquisition) ; Transfer (Zweitspracherwerb) ; Cross-linguistic influence (second language acquisition) ; Interference (second language acquisition) ; Sprachfähigkeit (Zweitspracherwerb) ; Spracheignung (Zweitspracherwerb) ; Language aptitude (second language acquisition) ; Gender ; Case (morph.) ; Number ; Conjugation; Verb inflection ; Clitics ; Griechisch; Greek (modern) ; Modern Greek ; Russian