El past simple se utiliza para referirse a acciones que ya terminaron en el pasado. 

Algunos ejemplos:

• I slept all night.

• She ate lunch at 12 am. 

• Did you go to the supermarket?

El past continuous se utiliza para describir acciones en progreso pero en un momento determinado del pasado.

Algunos ejemplos:

• I was running yesterday in the morning. 

• He wasn't answering the phone when I called. 

• Were you sleeping in work hours?

El past perfect se utiliza para describir acciones que ocurrieron antes de otra acción. 

Algunos ejemplos:

• She had already cooked the meal when I got home.

• He had visited the museum until last month. 

• The mail hadn't been sent when I went to the post office.

• Had you heard about it before today?

El past perfect continuous se usa al describir acciones que estaban en curso en el pasado pero fueron interrumpidas por otra acción o antes de un momento específico en el pasado. 

Algunos ejemplos:

• The girls had been playing outside for about an hour when it started to rain. 

• Clara needed a holiday because she had been working for six months. 

• Had they been playing video games all morning?