Q: I’m a native Polish speaker who’s learning vocabulary by solving English crosswords. During a coffee break at work, the clue “prison” suggested “jail” for these four spaces: “_A_L.” This sparked a debate with a British friend over “gaol” vs. “jail.” Your thoughts?

A: Both spellings have been around for hundreds of years. The traditional spelling has been “gaol” in Britain and “jail” in the United States.

Although “gaol” is still acceptable in Britain, it’s now considered a variant spelling of “jail” on both sides of the Atlantic, according to the Oxford English Dictionary and the four standard British dictionaries we’ve checked.

As Fowler’s Modern English Usage (rev. 3rd ed.) explains, “gaol, gaoler, the traditional spellings in the UK, are now under severe and probably unstoppable pressure from jail, jailer, which are dominant in most other parts of the English-speaking world.”

Both pairs—“gaol, gaoler” and “jail, jailer”—are pronounced the same way, which leads to this question: why do the British have a “gaol” spelling if the word is pronounced “jail”?

The short answer, according to Oxford Dictionaries online, is that the word “gaol” was “originally pronounced with a hard g, as in goat.” Here’s a fuller answer.

“Etymologically, a jail is a ‘little cage,’ ” John Ayto says in his Dictionary of Word Origins.

Ayto explains that the English word is ultimately derived from caveola, a diminutive of cavea, Latin for cage (and the source of the English word “cage”).

Why do we have two spellings? Because Middle English (the language spoken from about 1100 to 1500) adopted two distinct versions of the word from French.

The “gaol” version comes from the Norman French gaiole or gaole, the OED says, while “jail” comes from the Old Parisian French jaiole or jaile.

Early versions of “gaol” (like gayhol and gayhole) first showed up in English in the 1200s, while early versions of “jail” (iaiole and iayll) appeared in the 1300s, according to Oxford citations.

“Until the 17th century,” Ayto writes, “gaol was pronounced with a hard /g/ sound, but then it gradually fell into line with jail.”

The two versions of the word were spelled all sorts of ways in Middle English, when our language had no letter “j”: gayhol, gayhole, gayll, gaylle, gaille, gayole, and so on. The “gaol” and “jail” spellings first showed up in the 1600s.

The OED describes “gaol” as an “archaic spelling” that’s still seen in writing “chiefly due to statutory and official tradition” in Britain. However, the dictionary adds that “this is obsolete in the spoken language, where the surviving word is jail.”

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