Translation of traitorous in Spanish

The guy at the reception was pretty friendly and gave me keys of the hotel's suites. The first suite was again without windows. I returned and asked for the same with windows. He gave me other keys.
I understand that you use the article 'die' when talking about a feminine object, das when the subject is neutral, and der when talking about a masculine object. But how can you remember all these?
At Pisac we visited its 'once certainly authentic', 'today completely touristic' market. We enjoyed it anyway, ate fresh corncobs and bought a warm wool hat.