The Last Letter Added to English Alphabet Was J

For centuries, the letters I and J were essentially the same character, with "I" pulling double duty for both a vowel and a consonant sound. In Latin, for example, the name Julius would have been written as "Iulius." The visual distinction began with medieval scribes, who would often add a decorative tail, or swash, to the letter I, especially when it was the last letter in a Roman numeral (e.g., "xiij" for 13). This stylized "long I" was the forerunner of the modern J, but for a long time, it was considered just a stylistic variation, not a unique letter with its own sound.

The push for standardization came with the rise of the printing press. The formal separation of I and J is credited to Italian Renaissance grammarian Gian Giorgio Trissino in 1524. He championed using J specifically for the consonant sound (like in "jam") to make written Italian more phonetically consistent. The idea caught on slowly, and it took over a century for the distinction to become common in English. This late adoption is why the letter J is absent from original printings of Shakespeare's works and the 1611 King James Bible, where the name "Jesus" was spelled "Iesus." Its full acceptance cemented its place as the final addition to the 26-letter alphabet we use today.