What is the difference between formal and informal language?
This lesson in the English Advantage course deals with some of the differences between formal and informal language. It looks like this:
There are also some exercises in the Challenges & Skills channel of the VIP Community that can help you practise formal and informal language not only in writing but also in speaking:
Recorded Live Writing Lessons, especially those for Writing Task 1 (Academic or General Training), are also useful for learning more about formal and informal language.
Here is a link to some common formal vs informal words used in writing.
There is also a free app by Grammarly which checks for the tone of your writing. It may not be 100% accurate, but it will certainly give you a decent idea: https://www.grammarly.com/tone
