Pattern: Latin words that began with an ‘F’ tended to lose that initial ‘F’ sound and became silent (yet represented in writing with an ‘H’) as vulgar Latin turned into Spanish.
The Spanish rehusar — literally, “refuse” — sounds odd to English ears: it’s the same word, but the -f- became an -h-. Huh?
This is explained via the pattern of Latin words that began with an f- tended to turn into an h- in Spanish and only in Spanish. See famine/hambre, and huir/fugitive for example.
Refuse and Rehusar follow the same pattern. Both come from the Latin refundere — from which we also get the English, refund. They are all ways of giving back.
This f-to-h pattern usually happens with the first letter of the word. But here it is the first letter of the second syllable — because the re- is of course the standard prefix so it didn’t effect the sound pattern change.
The Spanish hechizo (“spell”; nothing to do with the letters in words, but what a witch casts on you!) comes from the Latin facticius (“made by art”; “artificial” — indeed, that which is artificial is just something not occurring naturally but instead made by art!).
But how did artificial change to mean “spell”? Think about it this way: casting a spell goes against nature — it’s what the wicked, crazy and profoundly unnatural woman does! Think of the three weird sisters in Macbeth, and how they unnaturally stir up all the elements!
From hechizo (more specifically, from it’s Portuguese twin cognate, feitiço), we get the English fetish. How? Well, you have a fetish when the recipient casts a spell on you to become obsessed with the object of your fetish, right? Enough said!
That root facticius turned into hechizo by changing via two common patterns: the initial F in Latin tended to turn into an H as Latin turned into Spanish (compare fig and higo, or fume and humo!) and the -ct- tended to change to a -ch- (compare noche and noctural; or ocho and octagon). Thus the h-ch of hechizo maps to the f-sh of fetish.
If he is fuming, he is smoking — literally. And it is, subtly, the same word in Spanish.
“To fume” comes from the Latin root fumus (“smoke”) from which we also get the common Spanish word for “smoke”, humo. But they don’t sound alike, so how are they related?
The Spanish humo is a great example of the pattern of the Initial F turning into an H in Spanish, alone among the languages of the world. Many Latin words that began with an F, and come to us in English through the Latinate F form, became the equivalent word but with an H- in Spanish. Take hermano and filial, for example. Or fact and hecho.
Other English words from the same root fumus include fumigation (ahhhh!) and the less common fetid. Fetid is a dirty, Shakespearean word, after all.
This gets very interesting very quickly, so note: