The Latin for “eight” is Octo, from which we get the English Octagon.

Since most Latin words with a -ct- sound, like Octo, had the -ct- turn into a -ch- as the language evolved into Spanish, it is no surprise that eight in Spanish is ocho.

This same pattern manifests itself in noche/nocturnal, leche/lactose, and is one of our favorite patterns here at ForNerds!

The Spanish for “chest”, pecho, sounds completely different than the English chest.

But it is related to the English word for the chest bones: the Pectoral Girdle.

The relationship is the Latin -ct- words transforming into -ch- as Latin turned into Spanish. Thus, the pect- maps to pech- exactly. The English word, on the other hand, is taken – unchanged – directly from the Latin.

Also from the same root, in Spanish, es pechuga — the common word for the common food, “chicken breast”!

The same pattern we see in noche/nocturnal, leche/lactose, etc.

The Spanish for “night”, noche, is related (via the common Latin ancestor) nocturnal.

Here’s the interesting part: the Latin sound “ct” consistently changed to the “ch” sound in Spanish. Think “lactose” and “leche”, or “octagon” and “ocho”. And this is another example of that pattern: the “ct” in “nocturnal” is the same as the “ch” in “noche”!

The Spanish Decir (“to say”) comes from the Latin dictio for “word”. Its participle form is dicho — and dicho also means “saying”, in the sense of, a cliche.

Thus decir is another example of the “ct” sound in Latin turning into the “ch” sound in Spanish — and is also related to the English word… dictionary.

The law and the good, in European languages, are associated with straight lines; the bad with the crooked. Think about the word crooked itself, literally! Or about right/rectangle, or the Greek ortho– for straight, hence, orthodox as well as orthodontics.

This is why it makes sense that Derecho — Spanish for straight and also for law — comes from the same Latin root that gives us direct.

The “ct” in the original direct turned into a “ch” in Spanish, in the usual pattern of “ct” turning into “ch” as Latin grew into Spanish.

Luchar, Spanish for “to fight”, doesn’t sound like its cousin reluctant – although of course everyone is reluctant to fight. But the relationship is closer than it seems.

Reluctant comes from the Latin roots re- (“against”) and luctari (“to fight”). Reluctance is to fight against what should be done — literally.

From luctari, we also get the Spanish for exactly the same, “to fight.”

But they don’t sound similar. How did luchar evolve?

Interestingly, in most Latin words that had a -ct- sound, this -ct- sound evolved into -ch- as Latin evolved into Spanish. Think about night/noche and eight/octagon. The same pattern explains luctari turning into luchar.

We see this relationship clearly with the l-ct to l-ch mapping between the two.

Suspect and the Spanish equivalent, sospechoso, are easy to identify and obviously the same word, both from the same Latin root, suspectus.

That’s not the interesting part. Rather, as Latin evolved into Spanish, the Latin sound -ct- turned into the Spanish -ch- sound. Think lactose/leche or octagon/ocho.

And suspect falls exactly into this pattern: the English s-s-p-ct maps exactly to the Spanish s-s-p-ch.