The word and constitutes just under 2.4% of all words used in the English language, although usage has decreased since its peak around 3.2% in the 1650s. According to my extensive collection of Zipf's Law graphics, it's the third most common word in the English language. Now, if we look at the etymology of and, we can see very little variation in both definition and spelling. This is unsurprising, as it is a fundamental word- so basic that there's not much to change. It's been around that long. In Old English, more than a thousand years ago, it was still a conjunction meaning "and", but if we go a quarter millennium back to Proto-Germanic, it was either unda or andi, depending on the reconstruction. Even further, in Proto-Indo-European, it actually had a different definition, that of "in", as the word en. Why? Not sure. It's tentative at best.
Hello! I'm Adam Aleksic. This year, I graduated from Harvard University with a degree in Government and Linguistics. There, I co-founded the Harvard Undergraduate Linguistics Society and wrote a thesis on Serbo-Croatian language policy, magna cum laude. In addition to etymology, I also really enjoy philosophy, trivia, vexillology, geography, board games, conlanging, art history, and law.