We use the Past Continuous to talk about an action that happened in the past and continued for a period of time. You always say the how much time the action lasts.
TO BE (PAST) + VERB-ING = I was jumping
EXAMPLES:
I was watching tv for two hours. While I was watching the TV, the telephone rang.
He was eating for 1 hour. While I was eating, the dog jumped.
She was working in the hospital for 3 years.
I was not watching tv for two hours
He was not eating for 1 hour
She was not working in the hospital for 3 years
Was I watching tv for two hours?
Was he eating for 1 hour?
Was she working in the hospital for 3 years?