Tense and Time

It is important not to confuse the name of a verb tense with the way we use it to talk about time.

For example, a present tense does not always refer to present time:

Or a past tense does not always refer to past time:

The following examples show how different tenses can be used to talk about different times.

TENSE TIME
past time present time future time
present simple   I want a coffee. I leave tomorrow.
She     likes     coffee.
continuous   I am having dinner. I am taking my exam next month.
They  are  living  in  London.
perfect I have seen ET. I have finished.  
perfect continuous I have been playing tennis.    
We have been working for four hours.  
past simple I finished one hour ago. If she loved you now, she would marry you. If you came tomorrow, you would see her.
continuous I was working at 2am this morning.    
perfect I had not eaten for 24 hours.    
perfect continuous We had been working for 3 hours. If I had been working now, I would have missed you. If I had been working tomorrow, I could not have agreed.
future simple   Hold on. I'll do it now. I'll see you tomorrow.
continuous     I will be working at 9pm tonight.
perfect     I will have finished by 9pm tonight.
We will have been married for ten years next month.
perfect continuous     They may be tired when you arrive because they will have been working.
In 30 minutes, we will have been working for four hours.