Interrupted continuous actions in the past (used in conjunction with the past simple) are formed when one action was ongoing at a certain point in the past and was interrupted by another action expressed in the past simple:

• When I arrived, they were serving lunch.
• I was sleeping when she called me.

Affirmative sentences in past continuous tense are structured with the formula Subject + was/were + verb (ing), such as:

• We got married when we were living in Moscow.

Negative sentences in past continuous tense are structured using the formula Subject + was/were + not + verb (ing), like in this example:

• They weren't waiting at the bus stop.

Interrogative structures in past continuous tense are formed by placing the verb 'was' or 'were' before the subject followed by the verb with 'ing':

• Question: Where were you living?
• Form: Was/were + subject + verb (ing)?