The Spanish hilo (cord; thread; string) comes from the Latin for the same, filum. The words sound very different, until we remember that, words in Latin that began with a f- tended to change to h- in Spanish: hijo/filium, and hoja/foliage, for example. Now the hilo/filum make sense!
Interestingly, however, from that same Latin root filum, we get various English words that also quietly show they are descendants of the word for cord or thread. Including:
Herir (Spanish for, “to round”; most commonly heard in the form, “herido”, a wound) is a surprising cousin of… interfere. How so?
Interfere comes to us from the French entre- (“between”) and ferir (“to hit”). Interfering with something is really just hitting it right in the middle of it, breaking it up! Ferir comes from the Latin, for the same, Ferire.
Curiously, Ferire evolved into Spanish Herir — the Initial “F” turning into a “H”. It turns out, this is a common pattern as Latin evolved into Spanish — but in no other language! Just look at Filial and Hijo, or File and Hilo, or Fig and Higo.
Thus, the h‑r of herir maps to the (int)-f‑r of interfere.
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.
The English fact comes from the Latin factum, meaning “something that happened.” It is thus an exact cognate to the Spanish hacer, meaning “to make.” How?
The root of both is the Latin facere, meaning “to do.” Fact, and the Latin factum, is just the same word in a different tense.
The Latin facere turned into the Spanish hacer, although they superficially sound different. Their relation becomes obvious once we remember that Latin words that began with an initial f- almost always turned into an initial h- when Latin evolved into Spanish.
Therefore the f‑c-r of facere maps exactly to the h‑c-r of hacer.
This pattern explains many words such as hierro/ferrari, hervir/fever, huir/fugitive, hoja/foliage!
A “shooting star” in Spanish is an estrella fugaz. Since estrella means “star”, then fugaz is the parallel to “shooting.”
Fugaz comes from the Latin fugere which means, “to run away; flee” — from which we get the English fugitive.
The mapping is obvious with the f‑g retained in both versions.
Thus, in Spanish, a shooting star is literally, a fleeing star. But fleeing from what?