Functions of the past continous

The past continuous describe actions or events in a time before now, which began in the past and is still going on at the time of speaking. In other words, its expresses an unfinished or incomplete action in the past.

• Often, to describe the background in a story written in the past tense.

For example, "The sun was shining and the birds were singing as the elephant came out of the jungle."

• To describe an unfished action that was interrupted by another event or action.

For example, "I was having a beautiful dream when the alarm clock rang."

• To express a change of mind.

For example, "I was going to spend the day at the beach but I've decided to get my homework done instead."