1. Use and practice

Teorie

https://www.helpforenglish.cz/article/2006072901-cleny-v-anglictine-articles

https://test-english.com/explanation/a1/aan-no-article-articles/


PROCVIČENÍ 

https://www.myenglishpages.com/english/grammar-exercise-articles-2.php

https://agendaweb.org/grammar/articles-beginners-exercises.html