Present Perfect or Simple Past?

Introduction

There are some differences between the Present Perfect Tense and the Simple Past Tense.

Has the time period finished?

Rule	Example	Explanation
The present perfect is used when the time period has NOT finished.	I have seen three movies this week.	(This week has not finished yet.)
The simple past is used when the time period HAS finished.	I saw three movies last week.	(Last week has finished.)

Is it new information or old?

Rule	Example	Explanation
The present perfect is often used when giving recent news.	Martin has crashed his car again.	(This is new information.)
The simple past is used when giving older information.	Martin crashed his car last year.	(This is old information.)

Is it a specific time?

Rule	Example	Explanation
The present perfect is used when the time is not specific.	I have seen that movie already.	(We don't know when.)
The simple past is used when the time is clear.	I saw that movie on Thursday.	(We know exactly when.)

Has the action finished (sentences with “for” or “since”)?

Rule	Example	Explanation
The present perfect is used with for and since when the actions have not finished yet.	I have lived in Victoria for five years.	(I still live in Victoria.)
The simple past is used with for when the actions have already finished.	I lived in Victoria for five years.	(I don't live in Victoria now.)

Exercises