Does sololearn teach responsive web designs?

Answer 1

You can make responsive web design using Bootstrap, here are lessons:
https://www.sololearn.com/learn/1051/?ref=app
Tutorials on another resources:
https://www.w3schools.com/css/css_rwd_intro.asp
https://www.w3schools.com/Html/html_responsive.asp

Answer 2

most of the basics needed for responsive websites is shown in the CSS lessons. but it's still a scratch on the surface.