Which is correct?
If you think you can rely on Microsoft Word’s grammar checker, you’ve got another _______ coming.
Colloquial, jocular and apparently ungrammatical though it is, “another think coming” is the original saying.
The Word Detective reports that “another think coming” appeared in print in the late 1800s and notes that, according to the OED, “thing” results from a “misapprehension” of the expression.
Proponents of “another thing coming” often argue that the original saying plays fast and loose with the laws of grammar, because “think” is a verb rather than a noun. TWD –AKA Evan Morris — explains why they’re wrong:
But guess what? “Think” is a noun as well as a verb. “Think” the noun first appeared around 1834 meaning “an act or period of thinking” (“Let’s have a cigar and a quiet think,” 1891), and, by 1886, “a thought” or “an idea” (“A thing must be a think before it be a thing,” 1887). We rarely see this noun form of “think” today (outside of this particular phrase), but in the late 19th century when the phrase became popular, “another think coming” would have been understood as equivalent to “another thought coming,” i.e., a change of mind.
Nevertheless, “another thing coming” is more common now than the original saying, which probably means that — should it not die out altogether — it will become the correct form. It’s not yet, though, so stick with “think” in informal writing and avoid the expression in formal writing. And if you think I’ll change my mind … well, you never know. It has happened.
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