“The principle may not come naturally, but surely we could make the particulars easier. If you were creating an alphabet for English from scratch, you would probably create 44 letters and match each speech sound with one letter. We’d call that one-to-one matching. Written English, alas, was not created from scratch. Our language is a mongrel: Germanic origins, heavily influenced by the Norman invasion and later by the adoption of Greek and Latinate words. That’s a problem because when we borrowed words, we frequently retained the spelling conventions of the original language. The result is that English uses a many-to-many matching. One letter (or letter combination) can signify many sounds, as the letter ‘e’ does: red, flower, bee.”
Excerpted from: Willingham, Daniel T. The Reading Mind: A Cognitive Approach to Understanding How the Mind Reads. San Francisco: Jossey-Bass, 2017.