Past Simple vs Present Perfect
A lot of students don't really understand the difference between two commonly used tenses the Past Simple and Present Perfect. Why don't we sort that out?
We won't discuss the formation of these tenses as you can listen about it in the podcasts ‘Past Simple' and ‘Present Perfect'.
Let's begin with the Past Simple.
We use the Past Simple to talk about actions and situations in the past which finished at a specific time. We usually use past time expressions such as yesterday, last week, an hour ago, etc. to show this.
Tom worked in Amsterdam last year.
(We know exactly when Tom worked in Amsterdam, it was last year).
Now let's move on to the Present Perfect.
We use the Present Perfect to talk about past actions and experiences without specifying the time because either it is unimportant or unknown.
Tom has worked in Amsterdam.
(We want to express that Tom has worked in Amsterdam and it is his life experience but it isn't important when it happened)
How about looking at more examples?
Jane saw a movie yesterday evening.
(It is obvious when she watched it, it was yesterday evening)
Jane has seen this movie twenty times.
(We don't know when she watched it, we know only she has seen this movie twenty times.)
I liked ice cream when I was a child.
(When I was a child is a phrase which shows us when the action happened)
I have never liked ice cream.
(It is difficult to specify the time in this sentence)
They danced a lot at the party last year.
(We know when, last year so we use the Past Simple)
They have danced a lot at the party.
(We don't know when, so we use the Present Perfect)
We did our shopping an hour ago.
(An hour ago is the time when we went shopping)
We haven't done our shopping yet.
(No exact time is mentioned in this sentence)
Whether we use the Present Perfect or Past Simple often depends on how we see the action. If we see it as related to the present, we use the Present Perfect.
J.K.Rowling has written the best-selling series of books Harry Potter. (Joan Rowling still lives and it is possible that she will write more books, so we have the connection with the present)
Shakespeare wrote a lot of plays. (William Shakespeare lived a few centuries ago, so this action has no connection with the present. We see it as finished and in the past, so we use the Past Simple.)
I hope you have understood the difference between these two tenses. One more time, the Past Simple we know when the action happened e.g. last year, in 1999, two weeks ago and it is finished, on the contrary we use the Present Perfect if we don't say when the actions and experiences happened.