English as a second language; ESL; TESOL ; Sprachenpolitik; Language management; Language politics ; Sprachattitüde; Linguizismus; Linguicism; Prestige; Sprachliche Unsicherheit; Linguistic insecurity ; Minoritätensprache; Minority language ; Bilingual education ; Mandarin; Kantonesisch; Cantonese; Putonghua; Sinitic; Hakka; Yue; Chinese ; Uyghur