Learn Spanish (Latin America): Es raro que aguantes a un chico tan grosero. - It is strange that you put up with such a rude guy.

The phrase es raro que (it is strange that) expresses an opinion or emotion about a situation. In Spanish, these kinds of impersonal expressions trigger the subjunctive mood for the verb that follows them, which is why we use aguantes instead of the indicative aguantas.

Does aguantar always mean 'to put up with'?

Aguantar is a very versatile and common verb in Latin America. While here it means 'to put up with' or 'to tolerate' a person, it can also mean 'to hold' (like holding your breath) or 'to endure' (like a phone battery lasting a long time).

Why do we need the a before un chico?

This is the 'personal a.' Even though un chico (a guy) isn't a specific named person like Juan or Carlos, it still refers to a human being receiving the action of the verb. When the direct object of a sentence is a person, Spanish requires this a before it.

Does grosero mean 'gross'?

It looks like it, but grosero is a false friend. It actually means 'rude' or 'impolite'. If you want to say something is 'gross' or 'disgusting' in Spanish, you would use words like asqueroso or repugnante.