First of all, try to put in your title a summarize about what the problem is, otherwise it will be like a box of surprises until you open the thread. I'm just give you a tip for the future,
To answer you question, go into options, Player 1 controls and check the play style option, then you simply change Standard (or Strafe) to Simple.
I know about a command that allows that, but i can't remember it right now