English has what linguists call deep orthography: https://en.wikipedia.org/wiki/Orthographic_depth. It has to do with the conservative nature of English spelling. English would rather maintain the same spelling for a word than have it accurately reflect the pronunciation. This makes English much harder to learn than languages with shallow orthography.

This is another reason why Esperanto remains a better international language than English. In Esperanto, each letter has exactly one sound, and there are no exceptions.