A British reader questions what he sees as a recent use of unbeknownst:
Curious about the current (British/Irish English only?) replacement of ‘unknown to him’ by ‘unbeknown/unbeknownst to him’ (university students’ work attests to it in yoof-speak, and BBC documentaries to it in them elder lemons what should beknow better). Is this also creeping into American English?
Partial paraphrase of the reader’s comment:
The writing of university students offers evidence that “unbeknownst to him” is current in youth slang, and the phrase occurs in BBC documentaries written by old-timers who should know better than to use it.
Although some speakers feel that unbeknownst “sounds medieval,” it is a fairly recent coinage, although not as recent as the reader seems to think: it dates from the 19th century.
The first OED citation is from a letter written by novelist Mrs. Gaskell:
You don’t see me, but I often am sitting in the rocking-chair unbeknownst to you. (1848)
The phrase “unbeknown to,” on the other hand, is documented as early as 1636. How the -st became attached to the word is—well—unknown.
A Google search indicates that the phrases “unbeknown to him” and “unbeknownst to him” are in use, but they rank far behind the more conventional “unknown to him”:
1. “unbeknown to him” About 151,000 results
2. “unbeknownst to him” About 391,000 results
3. “unknown to him” About 12,800,000 results
On the Ngram Viewer, Number One does not even show; Number Two makes a slight showing, and Number Three shows a marked decline in 1900, but remains well ahead of “unbeknownst to him.”
As for the phrase’s “creeping into American English,” it did that eighty-four years after Mrs. Gaskell used it—in Light in August by William Faulkner: “Interfering with his work unbeknownst to him.”
The use of unbeknownst in modern English is probably best described as “jocular” or “colloquial,” although it can be found in professional contexts:
Description of a car accident, NBC News
Unbeknownst to the first people who tried to help the victim of the crash, an adult male, the water was electrified.
Report of an experiment, Chicago Booth, publication of the University of Chicago Booth School of Business
Unbeknownst to them, the first part of the experiment served simply to expose them, in the form of a celebrity-trivia quiz, to pictures of high-profile, successful individuals.
Article about deception, Wired.
Unbeknownst to the subject, the boy is wearing a radio receiver in his ear, and every word he says is transmitted to him by a 37-year-old university professor sitting in a nearby room.
Article about stress of modern life, The New Republic
Unbeknownst to her at the time, a shooting had occurred the previous day in the same neighborhood.
Feature about racism among children, PBS Frontline
Unbeknownst to his parents, he had started a blog, which they only learned about when another parent called to warn them.