I know both words share the same meaning and pronunciation, but I wonder about their comparative usage in modern English.
Google Ngram Viewer (for the "British English" corpus) shows that gaol was more popular than jail until the mid-19th century, that the two words were used with broadly similar frequency from then until the mid-20th century, and that now jail is the most common spelling.
However, if you look at the actual citations you'll see that recent uses of gaol are largely in historical contexts (for example, historical studies of gaol records, or reprints of works like The Ballad of Reading Gaol) so that Ngram Viewer underestimates the modern dominance of jail.
|show 9 more comments|
British don't really use the word jail, jailed for 20 years can be used in text or news paper but to be sent to jail is a rare thing to say in the UK