The Indo-European root kaput, meaning “head”, led to words for the head in almost every western language, with no change.
The kaput turned into the almost-identical caput in Latin; and then that evolved, through very minor changes, to the almost-the-same cabeza in Spanish. The main sound shift is the p to b, but those are very clearly aligned signs that often swap.
Kaput, however, evolved into the German kopf — which then became the English head. How so?
The Germanic sound “k-“, as German evolved into English, generally became the “h-” sound in English. Take century/hundred or horn/cornudo or, my favorite, hemp/cannabis as other examples.
Thus, the c-b(-z) of cabeza maps to the h-d of head. In the English pattern of short, powerful words, the final sound was lost as well, to give us the simple, straightforward head.
One of our favorite patterns of sound change between English and Spanish is the sh/j shift: under the influence of arabic, many words that had a “s” or “sh” or “sy” or “ch” sound in Latin, started to be pronounced with the throat-clearing sound and written with a “j”. See sherry/jerez and chess/ajedrez or syrup/jarabe, for example.
Another example of this pattern is the Spanish word for “juice”, jugo. It comes from the Latin succus meaning, “juice” (particularly sap, or juice from plants).
From this Latin root succus we also get the English… suck.
Yes, if it sucks — it is juicy! Literally!
We can see the mapping in the s-c to j-g mapping. The “c” and “g” sounds are similar and often interchanged.
Interestingly, in Spain they do not say jugo to mean “juice”; instead, they say… suco. Suco, funnily enough, also comes from the same root of succus. It is just the variation that never underwent the arabic “j” transformation.
From the same root we also get the English succulent, although we do not get the superficially similar English juice, which comes from the Latin ius, meaning, “sauce.”
Enojar, Spanish for “to get angry”, has a fun cousin in the English, annoy.
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.
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.
The seemingly unrelated words are connected through the common transformation of Latin words beginning with an f- into an h- in Spanish, such as fig and higo, and fable and hablar.
Thus, the f-r-v of fervor maps to the h-r-v of hervir.
Ajedrez (Spanish for “chess”) sounds nothing like the English chess, so they can’t be first cousins… right?
Wrong. The Spanish “j” sound — pronounced with an Arabic-ish throat-clearing sound — was originally pronounced with a “sh” or “ch” sound. The arabic influence changed the pronunciation to be closer to the arabic: see sherry/jerez, for example.
Ajedrez and Chess are another example of this same interesting pattern. Try to imagine the “j” in ajedrez with a ch- sound and you almost get chess.
Both, curiously, come from the same Sanskrit word for the game: chaturanga (so the English ch- is thus preserved closer to the original sound — English didn’t have the arabic influence that Spanish did). And these came to both languages via the Persian, chatrang. The traders and travelers, after all, are the ones who change languages.