ESL (English as a second language),
ESOL (English for speakers of other languages),
EFL (English as a foreign language)
ELT (English language teaching)
TESL (teaching English as a second language),
TESOL (teaching English for speakers of other languages)
TEFL (teaching English as a foreign language) are all also used.
EAL (English as an additional language),
ESD (English as a second dialect),
EIL (English as an international language),
ELF (English as a lingua franca),
ESP (English for special purposes, or English for specific purposes),
EAP (English for academic purposes).
ELL (English language learner),
LEP (limited English proficiency)
CLD (culturally and linguistically diverse).