One mark, two jobs
A question mark tells readers that a sentence is asking something; an exclamation point signals force or sudden feeling. In a line such as “You did what?!”, the two marks make the reader process both cues in sequence. The interrobang compresses them into a single character: a question mark and exclamation point combined in one glyph, or printed letterform.
That makes it useful when the question itself carries the surprise. Instead of treating astonishment as an extra reaction after the question, the symbol presents the two tones together.
Why the combined mark stayed rare
The interrobang was proposed by advertising executive Martin K. Speckter in 1962, but a new punctuation mark needs more than a clear purpose to become routine. Writers must know it exists, readers must recognize it, and typefaces and input systems must make it easy to use.
Ordinary keyboards already offer the question mark and exclamation point, so “?!” works without special support. The interrobang asks people to adopt a less familiar character for a meaning they can already convey with two familiar ones. That practical advantage helps explain why the compact symbol remains a curiosity rather than a standard ending for astonished questions.
