Fun basic practice!
https://www.bbc.co.uk/learningenglish/english/basic-grammar
https://www.talkenglish.com/grammar/grammar.aspx
Intermediate practice:
https://www.bbc.co.uk/learningenglish/english/intermediate-grammar
https://learnenglish.britishcouncil.org/grammar/intermediate-to-upper-intermediate
Some more advanced practice, test yourself!
https://www.stgeorges.co.uk/online-english/english-grammar-exercise-for-advanced-levels
Practice for beginners!
https://www.bbc.co.uk/learningenglish/english/basic-vocabulary
https://learnenglish.britishcouncil.org/vocabulary/beginner-to-pre-intermediate
Fun intermediate practice!
https://www.bbc.co.uk/learningenglish/english/intermediate-vocabulary
https://learnenglish.britishcouncil.org/vocabulary/intermediate-to-upper-intermediate
Challenge yourself with this advanced practice:
https://www.memrise.com/course/254000/1500-advanced-english-words/
https://www.memrise.com/course/254000/1500-advanced-english-words/
Beginner exercises:
https://learnenglishteens.britishcouncil.org/skills/listening/beginner-a1-listening
https://www.youtube.com/watch?v=cC2vxmBDAG8
Fun intermediate practice!
Choose from thousands of stories: https://www.bbc.co.uk/learningenglish/english/features/6-minute-english
A drama about going to university:
https://www.bbc.co.uk/learningenglish/english/features/english-at-university
Test your skills with the harder stuff!
https://learnenglish.britishcouncil.org/skills/listening/advanced-c1
Fun basic practice!
https://www.fluentu.com/blog/english/learn-english-pronunciation/
https://www.englishclub.com/pronunciation/
https://www.youtube.com/watch?v=bKb6AeO8ynw
Intermediate exercises!
https://www.bbc.co.uk/learningenglish/english/features/pronunciation
For advanced speakers:
https://www.youtube.com/watch?v=oN1fP2Ffty4
Practice for beginners!
https://projectlifemastery.com/writing-tips-for-beginners/
https://www.dailywritingtips.com/writing-tips-beginners/
Been writing for a bit? This is for you!
https://learnenglishteens.britishcouncil.org/skills/writing/upper-intermediate-B2-writing
https://learnenglishteens.britishcouncil.org/skills/writing/advanced-C1-writing
https://thejohnfox.com/2016/05/creative-writing-exercises/
Remember: you can always write your own texts and take them to coffee time for comments!
Beginner exercises:
https://www.youtube.com/watch?v=DVp62QWVlgE
https://learnenglishteens.britishcouncil.org/skills/speaking/beginner-a1-speaking
https://learnenglishteens.britishcouncil.org/skills/speaking/elementary-a2-speaking
Some more advanced practice - test yourself!
https://www.youtube.com/watch?v=HV6h7MRrRNA
https://learnenglishteens.britishcouncil.org/skills/speaking/intermediate-b1-speaking
https://learnenglishteens.britishcouncil.org/skills/speaking/upper-intermediate-b2-speaking