how do i make it so there's no new inputs until the movement is done?

hi! i'm relatively new to coding, especially in lua, and i'm trying to make a game that involves grid-based movement but i'm having an issue in that the player can move before the last movement is finished, which ends up leading to things like diagonal movement and basically just messing up the grid movement setup lol-- i expect this is an easy fix but i couldn't rlly find anything online to help me out here so hopefully one of u can help!

local movey = game.Workspace.PlaceholderCharacter --movey is not a permanent character name lol
local usrinpsrv = game:GetService("UserInputService")
local score = 0


usrinpsrv.InputBegan:Connect(function(input)
	
	--controls!! this is coded so poorly
	
	--forward
	if input.KeyCode == Enum.KeyCode.W then
		score = score + 1
		print(score)
		for i = 1,8 do
			movey.Position = movey.Position + Vector3.new(0, 0, -0.5)
			wait(.02)
		end
		
	--left
	elseif input.KeyCode == Enum.KeyCode.A then
		for i = 1,8 do
			movey.Position = movey.Position + Vector3.new(-0.5, 0, 0)
			wait(.02)
		end

--right
	elseif input.KeyCode == Enum.KeyCode.D then
		for i = 1,8 do
			movey.Position = movey.Position + Vector3.new(0.5, 0, 0)
			wait(.02)
		end

	elseif input.KeyCode == Enum.KeyCode.S then
		score = score - 1
		print(score)
		for i = 1,8 do
			movey.Position = movey.Position + Vector3.new(0, 0, 0.5)
			wait(.02)
		end		
	end
end)

also, if anybody notices anything else wrong with the script that could be fixed please let me know! ty in advance!