I just got a very interesting question submitted: why is the plural of ox not oxes, but oxen (as contrasted to examples such as foxes, boxes, or poxes)? There are a couple other surviving -en words, like children, as the submitter pointed out, but for the most part our plurals are with an s. The reason lies in the competing influences from Anglo-Saxon and Proto-Germanic in the Middle English language. The Romantic, French, Anglo-Saxon plural was to add on an s, and the Germanic way was to add an n onto the ends of words. For a time, these suffixes coexisted peacefully, but eventually the s ending began to be more fashionable, and almost every word used it. However, language isn't uniform, and that's how we got these aberrations. It also helps that, in Old English, ox was spelled oxa, and it simply sounded better to keep on the n from the previous Proto-Germanic word ukhson (ultimately from Proto-Indo-Europan uksen, meaning "any male animal" in general)
Adam Aleksic, a leading contender for valedictorian of his high school, is a 208-month-old boy with disturbing interests in etymology, vexillology, geography, and law. Adam would like to one day visit Tajikistan and just won an essay contest on linguistics!
The Etymology Nerd