The word vigilasteis is the preterite form of vigilar in the second person plural.
See the full vigilar conjugation
¿Así que comprasteis uno de mis atuendos y vigilasteis mi apartamento todos los días hasta que me lo puse?
So you guys bought one of my outfits and then staked out my apartment every day until I wore it?
Want to Learn Spanish?
Spanish learning for everyone. For free.
The world’s largest Spanish dictionary
Conjugations for every Spanish verb
Learn vocabulary faster
Learn every rule and exception
Native-speaker video pronunciations
Word of the Day
Have you tried it yet? Here's what's included:
Learn offline on iOS
Learn Spanish faster