Present simple and continuous:
https://www.perfect-english-grammar.com/present-simple-present-continuous-1.html
https://www.perfect-english-grammar.com/present-simple-present-continuous-2.html
https://www.perfect-english-grammar.com/present-simple-present-continuous-3.html
https://www.englishtestsonline.com/present-continuous-present-simple-test-a2-b1-grammar-exercises/
Quantifiers:
https://test-english.com/grammar-points/b1/much-many-lot-little-no/ (there are three exercises)
https://elt.oup.com/student/solutions/preint/grammar/grammar_03_012e?cc=de&selLanguage=en
https://www.englisch-hilfen.de/en/exercises/confusing_words/few_little.htm
https://www.englisch-hilfen.de/en/exercises/confusing_words/much_many3.htm
https://www.englisch-hilfen.de/en/exercises/confusing_words/much_many2.htm
https://www.englisch-hilfen.de/en/exercises/confusing_words/much_many5.htm
Adverbs of frequency:
https://learnenglishteens.britishcouncil.org/grammar/a1-a2-grammar/adverbs-frequency (with explanation)
https://elt.oup.com/student/solutions/preint/grammar/grammar_03_012e?cc=de&selLanguage=en
https://elt.oup.com/student/solutions/elementary/grammar/grammar_02_012e?cc=de&selLanguage=en
https://test-english.com/grammar-points/a1/adverbs-frequency/
