Advanced Spanish: A serious problem....

I was recently sitting in the restaurant of a hotel close to the Lima, Perú airport, near a glass window separating the non-smoking section from the smoking section. A sign on the wall of the smoking section catches my attention, because it contains one of my grammatical pet peeves.

The sign reads: Fumar puede causar severos problemas con la salud…".

Anybody but me bothered by that?

The problem here is that a problem can't be severo; only your mom, your dad, your first grade teacher, a law, or a cop enforcing the law can be severo.

If a problem is bad, or serious, it's grave.

In other words when referring to something like an illness or a problem,  the English word severe does not translate to severo, but rather in Spanish is grave.

The Spanish word severo means "strict." Grave means "severe," or "serious."

So when you have a bad -- or severe -- disease, you have una enfermedad grave. If you have a serious problem, you have un problema grave.

Another error, probably even more egregious, is when someone wants to say "serious problem," so they say "un problema serio." The word serio means serious in the since of "sober," or "not funny."

Compare and contrast the two sentences below, one in English and the other in Spanish, but both saying the same thing:

My friend Mark is very serious, because he has a serious problem: his wife is very strict with him.
Mi amigo Mark es muy serio, porque tiene un problema grave: su esposa es un poco severa con el.