English as a second language

References:

1. 
   Lee, Paige. "TEFL / TESOL / TESL / CELTA / DELTA - What's The Difference". International TEFL Academy. Retrieved 15 July 2020.
   
2. 
   (Wright, W. E. (2010). Foundations for Teaching English Language Learners: Research, Theory, Policy, and Practice. Philadelphia: Caslon Publishing.).
   
3. 
   Horobin, Simon. "How English became English – and not Latin" Oxford University Press Blog. Retrieved November 18, 2017.
   
4. 
   P.D. Antony (8 August 2016). English Grammar and Usage Made Easy: Learning English Language and Grammar Made Simple. Notion Press. p. 8. ISBN 978-1-945688-07-2.
   
5. 
   Otto Dietrich (1890). Introduction to German, for Those who Have Some Knowledge of English Grammar. ... Phonography printing Company. p. 5.
   
6. 
   "What is TEFL?". International TEFL Academy. 2021. Retrieved 24 August 2021.