This is the script
local zeb=game:GetService("UserInputService")
zeb.InputBegan:connect(function(key)
if Input.Keycode=enum.Keycode.LeftShift then
game.Players.LocalPlayer.Humanoid.Walkspeed=50 else
game.Players.LocalPlayer.Humanoid.Walkspeed=25
end
zeb.InputEnded:connect(function()
game.Players.LocalPlayer.Humanoid.Walkspeed=25
end)
end)
it dont work..please help

4 comments
why did u enter this script into the player?
and i want the most simple easy low lines solution..and u didnt even explain this
^ Because you are accessing player's character's humanoid. So therefore, you insert the script inside the player.
What do you need explained? Point out parts / part of the script that you do not understand and Ill cut it down for you.