Simple present

FORM

[VERB+ed] or irregular verbs

Examples:

•You called Debbie.
•Did you call Debbie?

USE 1 Completed Action in the Past

Use the Simple Past to express the idea that an action started and finished at a specific time in the past. Sometimes, the speaker may not actually mention the specific time, but they do have one specific time in mind.

Examples:

•I saw a movie yesterday.
•I didn't see a play yesterday.

USE 2 A Series of Completed Actions

We use the Simple Past to list a series of completed actions in the past. These actions happen 1st, 2nd, 3rd, 4th, and so on.

Examples:

•I finished work, walked to the beach, and found a nice place to swim.

USE 3 Duration in Past

The Simple Past can be used with a duration which starts and stops in the past. A duration is a longer action often indicated by expressions such as: for two years, for five minutes, all day, all year, etc.

Examples:

•I lived in Brazil for two years.

USE 4 Habits in the Past

The Simple Past can also be used to describe a habit which stopped in the past. It can have the same meaning as "used to." To make it clear that we are talking about a habit, we often add expressions such as: always, often, usually, never, when I was a child, when I was younger, etc.

Examples:

•I studied French when I was a child.

USE 5 Past Facts or Generalizations

The Simple Past can also be used to describe past facts or generalizations which are no longer true. As in USE 4 above, this use of the Simple Past is quite similar to the expression "used to."

Examples:

•She was shy as a child, but now she is very outgoing.

Bibliography: http://www.englishpage.com/verbpage/simplepast.html