Even though it feels natural to English speakers, capitalizing I is unusual. In fact, English is the only language that does it.
Germanic and Romantic languages typically have some conventions for capitalizing proper nouns, like Deutschland (in German) or Place de la Concorde (in French), but English is the only one that insists on capitalizing the personal pronoun.
Still don’t think it’s weird … then why don’t we capitalize we?
How did we start capitalizing I?
It turns out that this unusual convention was a bit of an accident. In Old and Middle English, the word for I was closer to its German cousin, ich, and it was often spelled ic. At this point, the word was not capitalized. However, the pronunciation changed over time and so did the spelling, losing the consonant C.
At first, the new word, i, was left lowercase. By the time Chaucer wrote The Canterbury Tales in the late 1300s, I, the personal pronoun, was slightly taller than its lowercase equivalent. From that point on, it was typically capitalized.
Are there other single letter words in English?
The only other accepted single-letter word in English, a, is a larger presence on the page. Its appearance isn’t as offensive as the thin lowercase i.
Today, though, some of us are regressing. In e-mails and instant message conversations, capitalization conventions are backsliding. Do you think the capitalized I will go extinct?