From the archives...
The following question was originally posted on the (now discontinued) LOE Forum.
When I quote the rule "English words do not end in I, U, V, or J" (Spelling Rule 3) to people, I always get asked about taxi and alibi.
I explain that taxi is the shortened version of taxicab (which earns me an eye roll), but the argument really begins with the word alibi. It's derived from Latin, but isn't Latin a root of English?
Just looking for a bit of firepower for my next family gathering - lol!
Thanks for the question! Taxi is my new favorite, actually. I'd always found "taxicab" a sort of unconvincing explanation myself, but I just discovered — one of the benefits of reading older books, thank you G.K. Chesterton — that it's not actually the full story: "taxicab" is itself an abbreviation for taximeter cab. The Oxford English Dictionary says it's from a French word with the roots taxe + mètre (tariff-measuring). So a taxi or taximeter cab is the kind of cab that measures the distance and price automatically... in other words, the only kind we have now.
Now, onto alibi: Yes, you are certainly right that it is a Latin word, and also that many of our words come from Latin. But this one retains a Latin spelling pattern that isn't generally used in English words; its spelling wasn't Anglicized as many others. (We got our word circle from a Latin root, but we still don't call it a circus.) It is a Latin word that became commonly used in English, in its direct Latin form, in the 17th century, and eventually became naturalized like many other loan words (alumni, menu, tofu, etc.) without its spelling being changed. So it's not a Latin root used in an English word but an actual Latin word that we borrowed. About ninety percent of multi-syllable words in English are derived from Latin, but a much smaller percentage are loan words. (You can learn more about this on our blog: What is the difference between a loan word and an English word with foreign words?)