If any of you can actullay tell me what a "sudden" is,(which would be a noun), I will gladly accept your postulation that it is "all of a sudden", but since the term "all of the sudden" implies an adverb with "sudden" as a form of "suddenly", this form makes more sense gramatically. Not to mention that, "all of a sudden" does not imply an adverb, but implies the totality, (all), of the aforementioned "Sudden", and therefore, does not relate to time, which is the point of the saying, "all of a/the sudden", implying in a short span of time.Many of you have stated that you have only heard "all of a sudden" used all of your life, I am in my mid fifties and have never heard it used untill the last couple of years when all of the people started migrating here from the Northern states. As another poster mentioned, I don't care about where you are from, or what you say there, I am searching for the CORRECT usage.