Well, Whadya Know

How did that silent "b" get into the word "debt?"

I always had my doubts about silent letters, especially when
a teacher offered to help me remember them with a mnemonic.
Trying to get the spelling of "debt" right made me feel
particularly dumb. In that I may have had something in common
with the people of thirteenth century England, who
couldn't leave well enough alone.

You see the word, which came into English with the Norman
Conquest two centuries earlier, was originally spelled "det."
It came from the French word, "dette," meaning, well, you
know. In jolly Olde England they just loped off the last "e"
and totaled one of the "t's." So far, I like it.

But then the pedants got at it. They did a little research,
discovered that the French word came from the Latin,
"debita," and in the thirteenth century upgraded the English
version. For kids learning spelling, it's been tough going
ever since.
[source: Dictionary of Word and Phrase Origins by William and
Mary Morris]