You've Got Another Thing Coming vs. You Got Another Think Coming

"YOU'VE GOT ANOTHER THING COMING"

Unless you are quoting the song You've Got Another Thing Comin' by Judas Priest, you are misusing this phrase; actually, the song misuses the phrase as well.

"YOU'VE GOT ANOTHER THINK COMING"

"Another think coming" is the original form of the colloquial phrase aimed at someone who has a mistaken view. It comes from the old comical expression, "If that’s what you think, you’ve got another think coming."

Because "think" in the second part of the expression is (intentionally) ungrammatical, some people hear "another thing coming" and repeat it as such. Plus, "another thing coming" usually makes literal sense, so it’s now more common than "another think coming."

The exact origins of "another think coming" are mysterious, but it appears to be an Americanism, and it does predate "another thing coming" in the sense of expressing disagreement. It goes back at least a century. Here are a few old examples:

• "Having elected him republicans think they have some voice in the distribution of the spoils and there is where they have another think coming to them." - The Daily Argus (1897) 
• "Those who thought taxes high in the past will have another think coming in the future." - Clinton Mirror (1907)
• "If this Good Will Campaign is not a close race then you have another think coming." - Steuben Farmers’ Advocate (1925)