DESI; Study of German and English Proficiency ; Composition (teaching of) ; English as a second language; ESL; TESOL ; GERS; CEFR; Quadro Comune Europeo di Riferimento; Common European Framework of Reference for Languages ; Zweitspracherwerb (Textproduktion) ; Second language acquisition (text production) ; Text production (second language acquisition) ; Evaluation criterion (text.) ; English