Learn French: Je suis arrivé il y a longtemps, mais je rentre bredouille. - I arrived a long time ago, but I return empty-handed.

You could say J'ai beau être arrivé il y a longtemps, je rentre bredouille (Even though I arrived a long time ago, I am returning empty-handed). Because avoir beau must be followed by an infinitive, and the arrival happened in the past, we use the past infinitive: the infinitive of the helping verb (être) plus the past participle (arrivé).

What exactly does bredouille mean?

Bredouille is an adjective that means 'empty-handed' or 'unsuccessful'. It is almost always paired with verbs of movement like rentrer or revenir (to come back). The phrase rentrer bredouille originally comes from hunting or fishing to describe coming home without catching anything, but today it is used for any unsuccessful trip, like going shopping and buying nothing.

I learned that il y a means 'there is'. Why does it mean 'ago' here?

When il y a is followed by a time expression, it changes meaning to 'ago'. So while it literally looks like 'there is a long time', il y a longtemps translates perfectly to 'a long time ago'. You can use this with any time duration, like il y a deux semaines (two weeks ago).

Why does the sentence use rentre instead of retourne for 'return'?

Rentrer implies returning to your home, your base, or where you belong—which fits perfectly with coming home empty-handed at the end of the day. Retourner means going back to a place you don't live (like returning to a store or a restaurant you just left).