Verb conjugation of "clavar" 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.
But we need to asked ourselves why we actually are built in such a way that we so easily dislike others and build stereotypes. What leads to such behavior even in well educated individuals?
We managed to get a few hours of bad sleep and arrived at the destination called Lao Cai, the capital of the province with the same name. It was only 370km from Hanoi, but the ride lasted nine hours.