present perfect VS past simple

PAST SIMPLE:

Use the past simple when you talk about things which happened and finished in the past, The past simple means a finished time and does not tell us the present. Watch out these words, yesterday, last year, two months ago, in 1980,

I missed the bus this morning.
It rained all last summer.

PRESENT PERFECT:

The present perfect tells us about the past and about the present. We look back from the present. We can use present perfect for an action in a period leading up to the present. The period of time may cover the whole of someone’s life up to the present.

He has not eaten beef all his life.
He has lived in this house since 1981. (He moved into the house in 1981 and he is still living there.)
We have only had two customers all evening.

It can be an action in the past which has an effect or result in the present.
He has lost the key. (He lost the key some time in the past and as a result he cannot open the door.)

It can be something that happened a very short time ago.
I have already eaten.
I have not eaten yet.
He has just scored a goal.
The weather has been terrible lately.
I have not worn these trousers recently.

Past simple or present perfect?

She worked in that bank for four years. (She does not work there now.)

She has worked in that bank for four years. (Working in the bank has continued up to the present and she may or may not go on in the future).

I was there from three o’clock to five. (Then I left).

I have been here sine three o’clock. (I am still here.)