I can't run in the game minecraft, my person is stuck in walk mode. What button makes me able to walk again?

The shoulder button on the left side.

It's not a button actually. Also to answer that question if you are playing on Xbox and you know how to walk then all you have to do is walk stop and walk again but super quickly and if on computer than quickly press w twice but on the second press is not a press it's a hold so you quickly press w and then hold w and you'll be running