The Spanish llamar (to name; commonly used to say “My name is”: “Me llamo” is literally, “I call myself…”) comes from the Latin clamare, meaning “to cry out, shout, proclaim.”
This is an example of the pattern where Latin words beginning in “Cl” are changed to the double-l (“ll”) in Spanish. In English, these words retain the “cl” sound – from the same root we get claim and clamor.
Other examples of this pattern include llave and clef.
Ducha, Spanish for “shower”, sounds unrelated to the English for the same. But it does have a less obvious cousin in English: duct; both do conduct water, towards a particular direction!
And yes, from the same root we also get, via French, douche, as in, douchebag.
Duct and Ducha both come the same Latin root, ductus, “leading”. More on that one another day.
The transformation happened due to the always-fun pattern of the -ct- words in Latin turning into -ch- words in Spanish. Thus, the d-ct in Latin and English maps almost exactly to the d-ch in Spanish.
Fervor is really just an intense passion heating up. Thus we shouldn’t be surprised that it comes from the Latin root fervere (“to boil”), from which we get the Spanish for the same (“to boil”), hervir.
Thus, the f-r-v of fervor maps to the h-r-v of hervir.
Both of these (along with the French for “worldly boredom”, ennui) come from the Latin inodiare, meaning, “to hate”. The Latin in- adds emphasis to the odium, Latin for “hate”.
We can see the parallels in all with the open vowel, followed by the -n-, followed by a -y- sound, although in Spanish the -y- sounds (and its corresponding -x- and -sh- variations) often turned into the -j- sounds, as it did here. Thus, the a-n-y maps to the e-n-j.
Hatred, then, dissipates and weakens over time. In English, hatred weakens into mere annoyance. In Spanish, hatred weakens into just anger, enojo. And, best of all, hatred in French weakens into a world-weary boredom of ennui.
Chief, and the Spanish for the same, Jefe, both come from the same root: the French chef, which means the same.
But this is odd as they sound so different! How are they related?
It’s not obvious, but it’s easy once you understand the pattern: The Latin sound “sh” and very similar sounds (such as the “ch” and “sy”) almost always became a “j” in Spanish. Like syrup and jarabe. Not obvious!