So...past simple or continuous?

Past simple and continuous, explained in Spanish:

http://www.vitutor.com/gramatica_inglesa/verb_tense/past_simple_continuous.html

Past simple and continuous, explanation in Spanish and exercise:

http://www.aulafacil.com/Ingejerc/Lecciones/Lecc19.htm

Explanation in video:

http://www.blueblocnotes.com/grammar/past-tenses/past-simple-and-continuous

Past simple and continuous. Summary in Spanish:

http://www.english-area.com/paginas/pasadosimplevspasadocontinuo.pdf