Can anyone teach me how to use TweenStatus?

TweenStatus is an Enum that tells you whether a tween was completed or cancelled because another tween overwrote it. It's only used for GUI tweening.

local gui = ...

local function tweenCallback(tweenStatus)
	if tweenStatus == Enum.TweenStatus.Canceled then
		print("tween was cancelled :(")
	elseif tweenStatus == Enum.TweenStatus.Completed then
		print("tween finished :)")
	end
end

gui:TweenSize(_, _, _, _, _, tweenCallback) --> When the tween stops, it'll call tweenCallback with a TweenStatus