Word level test ; English as a second language; ESL; TESOL ; Wortschatz (Sprachunterricht) ; Lernwortschatz; Vocabulary teaching ; Worthäufigkeit; Häufigkeitsliste; Frequency list; Frequency (lex.) ; Word frequency ; Zweitspracherwerb (lex.) ; Second language acquisition (lex.) ; Vocabulary (second language acquisition)