Formal vs informal English - corso BE

https://www.youtube.com/watch?v=hdKYl8Tg_FQ

http://www.engvid.com/writing-letters-formal-informal-english/

https://www.youtube.com/watch?v=llqPvcciKEM

https://www.cambridgeenglish.org/learning-english/activities-for-learners/c1w001-formal-and-informal-writing

https://www.bbc.co.uk/learningenglish/course/towards-advanced/unit-19/session-1

http://www.engvid.com/english-resource/formal-informal-english/



http://www.esl-lounge.com/student/reading/3r8-formal-informal-letter.php

http://www.autoenglish.org/writing/formalandinformalexercise.htm

https://www.flo-joe.co.uk/cae/students/writing/register/index.htm

https://eslflow.com/letterwriting.html