Correr comes from the Latin for the same, currere. Currere, in turn, comes from the Proto-Indo-European root *kurs, which also means, “to run” — just like horse does! Both have the same common ancestor.
The weird thing is: how did the PIE *kurs turn into horse, they sound so different.
The explanation is that, in the Germanic languages like English, the k- sound turned into the h- sound. But in Spanish, the original k- sound remained, although usually written with a c-.
Think about base as the core foundation or support — the lowest thing holding everything else up — or even in the old Shakespearean sense of “vile”, “the basest weed” — the connection makes much more sense.
Both come from the Latin basis (meaning, “foundation”) — from which we also get the same English, basis.
And think of the bass cleff in music, for the lower notes, as well.
The surprising connection is explained easily when we understand that a lot of sh- and si- and related sounds in Latin turned into j- in Spanish. Thus, the b-s maps to b-j almost exactly.
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?
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.
From the same root, however, also comes the English ineffable, that SAT word meaning “unable to be described in words.” So, ineffable literally means “without” (in-) and “speaking” (fabulare).
We see the h-b-l of hablar map to the (in-)f-b-l of ineffable quite clearly!
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.