Language travels from place to place, and mixes and merges with other languages. It’s been happening that way for a long time, it’s just that sometimes we forget and wonder why some words don’t follow rules. It’s because of the language of origin.
In my Theories of 2nd Acquisition Language class, one of my classmates, Josh explained how much of a mutt the English language is. Why does it have so many more phonemes than the Hawai’ian language for instance. The Hawai’ian language is a very simple language. However, it’s a pure language, while English is not.
This came up because I was asking my teacher how to explain to my students why “ea” in weather doesn’t follow the “when two vowels go walking” rule; why isn’t it pronounced more like weether instead of the way it is. That’s when we had a great discussion about it.
So, the next time you think about trying to explain why, just save yourself some time and tell them that that particular word is a rule-breaker.