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.