Here's a breakdown of the evolution:
* Latin: "hau!" (greeting)
* Old Spanish: "óla!"
* Modern Spanish: "hola!"
It's interesting to note that the "h" in "hola" is silent. It's simply a remnant of the original Latin phrase, which makes it even more intriguing.
So, the next time you say "hola" to someone, you can think of the ancient Latin roots of this common greeting!