Vocational school ; DaF; Deutsch als Zweitsprache; German as a second language; DaZ; German as a foreign language ; Illiteracy ; Ausspracheregel (Sprachunterricht) ; Pronunciation rule (language teaching) ; GPK (Sprachunterricht) ; Grapheme-phoneme conversion rule (language teaching) ; Lehrplan; Instructional advice ; Metalinguistic awareness; Phonologische Bewusstheit; Phonological awareness; Focus on form (language teaching) ; Sprachbewusstsein; Linguistic awareness ; German