There are three basic tenses:
These basic tenses can have three aspects:
The Simple Aspect
… is used to describe habits or facts – in past, present and future.
“When Fido was still alive, we usually went on a walk three times a day.”
“We always go on holiday to Brighton. We just love the open atmosphere there.”
“Friends will be friends.”
The Progressive Aspect
… is used to describe an action that is, was or will be ongoing / dynamic.
(lat. progressus => progredi = “moving forward”)
“I was walking down the street when she saw me.”
“Don’t disturb me! Can’t you see I am working?”
“I will be working in the garden by the time you arrive.”
The Perfect Aspect
… is used to describe an action that had, has or will have just been completed.
(lat. perfect => perficere = “finished”)
“What a shame – the plane had just left before we arrived at the airport.”
“I’m sorry I don’t have any food home.” – “That’s alright, we have just eaten.”
“By the time you move out, I will have lived in New York for three years.”
Also, a combination of perfect and progressive is possible:
The Perfect Progressive Aspect
… is used to describe the end of an action that is ongoing.
“I had been cooking for half an hour before Melinda rang at the door.”
“You don’t know Leicester Square?” – “I’m sorry, I have only been living here for three months.”
“I will have been working out for two hours by the time you arrive at the gym.”