Dialogue module marking everything as punctuation?

so i have this modulescript here that will check if the last character in the text is a period, question mark, exclamation point, comma, colon, or semicolon, but for some reason, it's marking every character as a period/question mark/exclamation point. i think this might have to do with the or statements? here's the code:

local player

wait(1)

player = game.Players:FindFirstChildWhichIsA("Player")
local db = player.PlayerGui.ScreenGui.DialogueBox

function Dialogue(text)
	for i=0,string.len(text) do
		db.Text.Text = string.sub(text, 1, i)
		player.PlayerGui.Beep:Play()
		if string.sub(db.Text.Text, string.len(db.Text.Text)) == "." or "?" or "!" then
			wait(1)
		elseif string.sub(db.Text.Text, string.len(db.Text.Text)) == "," or ";" or ":" then
			wait(0.5)
		end
		wait()
	end
	wait(1)
	game.ReplicatedStorage.DProgressed.OnServerEvent:Wait()
end

return Dialogue