January 30, 2014 tesolAmerican TESOL Institute Acronym Overload: The Difference Between TESOL, ESL, & TEFL TESOL, TESL, ESL, CELTA, & TEFL certifications are credentials to teach English as a second language. Explore various concepts of certification and their acronyms. ESL, TESOL, TEFL, CELTA, and TESL: […]