Why English spelling doesn't match how words sound

Around 1400, English spelling roughly matched speech. Bite sounded close to "beet", meet roughly like "mate", and house like "hoose".

Then, over about three centuries, the long vowels of English moved up in the mouth one after another. This was the Great Vowel Shift. At the same time, printing arrived with William Caxton in 1476, and spellings began to settle. The letters stayed where they were while the sounds kept moving.

Add French scribal habits, a Flemish h in ghost, and Renaissance scholars who put a silent b into debt, and you get modern English spelling.