The Grammar section of our site allows users to practice different types of grammar:
Comparatives: https://askpaulenglish.com/comparatives/
First Conditonal: https://askpaulenglish.com/1st-conditional/
Obligations: https://askpaulenglish.com/obligations/
Past Simple: https://askpaulenglish.com/past-simple-2/
Present Continuous: https://askpaulenglish.com/present-continuous-2/
Present Perfect: https://askpaulenglish.com/present-perfect/