Hervir (Spanish for, “to boil”) comes from the Latin fervere (“to be hot, burn, boil”).
The best part: from this same root, we also get the English… fever!
This is thus another example of the pattern where Spanish lost the initial F and replaced it with the (unspoken) “H”: Hoja-Foliage, Huir-Fugitive, etc.
“Fig” comes from the Latin “Ficus” — obvious enough!
But, curiously, the Spanish word is “Higado”. Huh?
This is just a simple example of the Initial F to H pattern. In lots of Latin words, the first F became an H when Latin evolved into Spanish. Think fact/hecho or hablar/fable.
An easy way to figure out what an H- word in Spanish is: change the initial H to an F and see what English word sounds similar.
The Spanish hambre, for “hunger”, makes sense if you know two different patterns.
Firstly, the initial f-to-h pattern: words that began with an f- then a vowel in Latin tended to have the f- turned into an h- when Spanish evolved into Latin. Huir and Fugitive is another example of that pattern.
Secondly, the mn-to-mbr pattern: when the letters in Latin “m” and “n” appear together, often separated by a vowel, they usually became “mbr” as a unit in Spanish.
Thus the f-m-n of famine maps directly to the h-m-b-r of hambre.
Hierro is just Spanish for “iron”.
Here’s where it gets interesting: the Latin words beginning with f- generally turned into the silent h- in Spanish but not in the other Romantic languages, and thus hierro (from the Latin ferrum) is related to:
The Initial F, followed by a vowel, disappears: So, “hoja“, meaning “leaf” (in all senses: the autumn trees, the piece of paper) is thus, from the same Latin root as “foliage“, the green plant leaves!