The "A21" refers to a specific level within the course, which corresponds to level A2.1 according to the Common European Framework of Reference for Languages (CEFR). This level focuses on basic language skills for everyday situations.
(Coursebook) and follows a modular structure that breaks down the A2.1 level into digestible lessons. Grammar & Vocabulary menschen a21 arbeitsbuch pdf updated
Ein Wochenende voller Überraschungen (A Weekend Full of Surprises) The "A21" refers to a specific level within