What s the difference? Present perfect and Past simple

What s the difference? Present Perfect and Past Simple
1. We use the past simple for past events or actions which have no connection to the present.
2. We use the present perfect for actions which started in the past and are still happening now OR for finished actions which have a connection to the present.
3. We CAN T use the present perfect with a finished time word:
NOT: I ve been to the museum yesterday.
Present Perfect Simple
Unfinished actions that started in the past and continue to the present:
• I ve known Julie for ten years (and I still know her).
Past Simple
Finished actions:
I knew Julie for ten years (but then she moved away and we lost touch).
Present Perfect Simple
A finished action in someone s life (when the person is still alive: life experience):
• My brother has been to Mexico three times.
Past Simple
A finished action in someone s life (when the person is dead):
My great-grandmother went to Mexico three times.
Present Perfect Simple
A finished action with a result in the present:
• I ve lost my keys! (The result is that I can t get into my house now).
Past Simple
A finished action with no result in the present:
I lost my keys yesterday. It was terrible! (Now there is no result. I got new keys yesterday).
Present Perfect Simple
With an unfinished time word (this week, this month, today):
• I ve seen John this week.
Past Simple
With a finished time word (last week, last month, yesterday):
I saw John last week.
Past Continuous Tense The past continuous tense, also known as the past progressive tense, refers to a continuing action or state that was happening at some point in the past. The past continuous tense is formed by combining the past tense of to be (i.e., was/were) with the verb’s present participle (-ing word).
There are many situations in which this verb tense might be used in a sentence. For example, it is often used to describe conditions that existed in the past.
The sun was shining every day that summer.
As I spoke, the children were laughing at my cleverness.
I was making dinner when she arrived.
At 6 o’clock, I was eating dinner.
She was talking in class .