Verb conjugation of "concretar" in Spanish

I ordered a cab at four o'clock in the morning which took me to the Central Bus Station. I was much to early because the bus would go just at seven o'clock. Anyway I was sitting there and listening to music.
It seemed like a very cute settlement and a great place to stay in for a night or two and I hoped that they would have rooms. However, since I wasn't sure I decided to carry my backpack with me.
Eating in that Sushi place was fan as everybody was greeted loudly whenever entering the restaurant. The quality of the Sushi was not the best, it was a fast food place, but we really enjoyed it.