English as a second language; ESL; TESOL ; Wortschatz (Sprachunterricht) ; Lernwortschatz; Vocabulary teaching ; Gesture communication ; Classroom communication; Instructional communication ; Semantization (second language acquisition) ; English (American) ; USA (English language in the) ; USA (engl. Sprache in den) ; English in the USA; Englisch in den USA; American English