How to say i was in Spanish

The Spanish translation of i was is yo estaba.
How to pronounce yo estaba in Spanish:
Click to hear the pronunciation of yo estaba  
Examples of yo estaba in Spanish:
Yo estaba seguro de que nadie me había visto.
I was sure that nobody had seen me.

Yo estaba haciendo la tarea.
I was doing my homework.

Yo estaba estudiando.
I was studying.

Do you know another example that uses i was in Spanish? Please tell us where you read or heard it (including the quote, if possible).