In your fictional world, do your humans walk on two legs or on all fours?

A question inspired by the news of a new dinosaur movie coming soon.<br><br>In my world humans evolved from primates a long time ago and walked on 2 legs. However, on one planet that I'm working on, humans evolved from big cats, and there humans walk on 4 all the time. Another planet I have, humans evolved from dolphins, and they always swim.<br><br>How do your humans walk in your world? Do they always walk the same way, or do they switch between two ways depending on the situation?