The tenth letter of the English alphabet. The letter "J" didn't exist as a letter until Medieval Latin, when it was used interchangeably with the letter "I." It was also pronounced as the letter "I," its only distinction being that it tended to be used as an initial letter and as a consonant (similar to the "Y" sound). In quite recent times, under the influence of French, it began to be used as the "dg" sound we use often today.