Past Simple or Present Perfect?

Hi, my name is Rebecca and in today's lesson

We're going to talk about a common error made by students when they use two tenses in English

These are the past simple and the present perfect

Now in case you're not sure exactly what those are let's review, and then I'm going to point out

What's the mistake that students often make when they start using these two tenses. All right?

So let's look at the board

So let's think first about time

We can divide time into two categories

Time which is finished and over and time which is unfinished. What do I mean by that?

Time which is finished is easier to understand. It's things like

yesterday last week, last year

and so on right. It's over. It's fairly finished

Unfinished time could be for example today

Today is still going on. It's not over this year is

Still going on. It's unfinished

So what you have to keep in mind is that when we are talking about finished times?

we need to use the past simple and

when we are talking about

unfinished times

We should use present perfect

Let's look at an example. So you understand more specifically, okay?

Let's take this sentence. I worked hard

yesterday

That would be fine to say because yes finish time or I could say I worked hard last week

also finished

I could say I worked hard last month right those are all correct because we're using the past simple and

we're using a finished time with them which would be correct

we can also say if we're talking about

present and present perfect, we could say I have worked hard, right?

I have worked hard. Which is the present simple.

This week I have worked hard this week

Now I'm using an unfinished time because the week is not over so it's unfinished

I have worked hard this semester

Let's say you're in university, right ?

I have worked hard since

January

Since January means from January till now and including now

so it's an unfinished time right so we can use this with present perfect or

I have worked hard since 6:00 a.m.

Since 6 o'clock this morning right and now it's still today, so it's an unfinished time all right

So this is what you need to keep in mind regarding

Time and it's one small way in which you can

Know whether to use past simple or the to use present perfect. The most common error is that?

When students learn the present perfect they sometimes like it a lot and they want to start using it

But then they use it with a time which is finished

so if we look at the example here of Niagara Falls the

correct example would be I visited Niagara Falls on

Saturday let's say today day is Sunday or Monday so at Saturday in the past. It's over. It's finished

So I could say I visited Niagara falls on set for I visited Niagara falls last summer

Right last weekend anything like that

Or if I want to talk about, Niagara falls here

I could say I have visited Niagara falls many times in my life

now presumably

My life is unfinished right now. I'm still alive

So we're talking about an unfinished time, so you could say I have visited Niagara falls many times in my life

So that would also be correct what happens is that sometimes students start to say I have visited, Niagara Falls

last Saturday

or I have visited Niagara falls last summer that would be wrong because you're

mixing present perfect with the finished and that's

The mistake that we want to avoid okay, if you'd like some more practice on this please feel free to visit our website

www.engvid.com

you'll see a quiz there, and that will help you to master this little point that might cause you some problems in English

Okay, all the best with your English bye for now