FORM: [was/were + present participle]
The past continuous of any verb is composed of two parts : the past tense of the verb to be (was/were), and the base of the main verb +ing
The past continuous describes actions or events in a time before now, which began in the past and was still going on at the time of speaking.
It is used:
- Often, to describe the background in a story written in the past tense.
- To describe an unfinished action that was interrupted by another event or action: "I was having a beautiful dream when the alarm clock rang."
- To express a change of mind: e.g. "I was going to spend the day at the beach but I've decided to go on an excursion instead."
Afirmative:
* I was studying when she called
Negative:
*I wasn't studing when she called
Interrogative:
*Was I studing when she called?
It is important to remember that non-continuous verbs can't be used in any continuous tenses. Also, certain non-continuous meanings for mixed verbs can't be used in continuous tenses. Instead of using Past Continuous with these verbs, you must use simple past.
- Jane was being at my house when you arrived. Not Correct
- Jane was at my house when you arrived. Correct
Credits: http://www.englishpage.com/verbpage/pastperfectcontinuous.html
