many learners already speak more than one language. A counter-argument says that the word "a" in the phrase "a second language" means there is no presumption that English is the second acquired language (see also Second language). TESL is the teaching of English as a second language. There are also other terms that it may be referred to in the US including ELL (English Language Learner) and CLD (Culturally and Linguistically Diverse).

In the UK and Ireland, the term ESL has been replaced by ESOL