Time and Tense

Depending upon how we count them, English can identify about thirty-six different times.

Time
The first word of a verb is the finite form. With any verb except a modal, it shows the main time: past, or present, or future.
She played football. (past)
She plays football. (usual present, not now)
She will play football. (future)

Before the Main Time
If we want to talk about two times in one sentence, we can use the perfect form – (have) + past participle – for the earlier time.
She had played football, so she learnt hockey quickly. (both past, football before hockey)
She has played football, so she can learn hockey quickly. (football past, hockey future)
She will have played football, so we can have her on our team. (football before have)
Because the perfect form means “before”, the future perfect (will have done) might be before now and it might be after now: the tense only tells us that it is before the main time of the sentence.

Around the Main Time
If we want to put the verb around the main time, so that the main time happens in the middle of the action, we use a continuous form: (be) + present participle.
She was playing football when I called her. (The football started before and ended after my call; the call was during the football game.)
She is playing football. (Right now, she is in a football game.)
She will be playing football when you come home. (The football will start before and end after you arrive home; your arrival will be during the football game.)

After the Main Time
If we want to talk about two times in one sentence, we can use the (Progressive Future) form – (be) + going to + infinitive – for the later time.
Because she was going to play football later, she didn’t eat a big lunch.
She is going to play football in five minutes.
She will be going to play football after she finishes school tomorrow.
The last one is very unusual, because we do not usually need to talk about something happening after another time in the future.

After a Time before the Main Time
We can combine the perfect and the progressive future, especially if we want to talk about a plan before another time. We do not often do this, but native speakers can understand it because English’s verb tenses are a system.
She had been going to play football, but she twisted her ankle.
I have always been going to visit Iceland. Perhaps I will go there next year.