Here's the British Council's explanation: Here are three reasons why English has so many silent letters: Old English was 90% phonemic (words sound the same as they look). But from the beginning of the 15th century, we began to borrow words from other languages. Because grammar and usage rules are different in other languages, adopted words did not follow the rules of English pronunciation.
New words, one handy idiom, and a 2-minute quiz — delivered to your inbox to keep your streak alive.