Hello everyone, I'm Nick Shepherd, welcome
If you say, "What have you been doing?"
You mean recently, up to now,
It's about the past
But it connects the past to the present.
The connection could be real . . .
You started in the past and you're still doing it,
like my first sentence.
I'm still working on the video
. . . or it could be figurative.
Oh, goodness, I don't know, sometime last century
You've been doing it in the past,
and you'll probably do it again
but you may not be doing it right now.
And here are the two diagrams together.
On the left you can see the present progressive,
happening around now or even right now,
and on th right. the present perfect progressive,
starting the past,
and going up to the present
in one way or the other.
Now let's look at two words which often show up with these forms,
We use FOR to talk about a period of time.
Which tense we use depends on where we are . . .
. . .in the period of time.
Here's a period of time.
At the beginning of the week, we say:
At the end of the week, we say:
And in the middle, we can say either one.
At the beginning, we see a temporary event
close to the present.
At the end we see something in the past,
leading up to the present.
In the middle, we can go either way.
Now, there are four sentences there,
and in three of them we can use 'for a week'
instead of 'this week'.
The first one, as an extended temporary present time
The last one, past time leading up to the present
and one of the ones in the middle,
as an extended present,
but not the second one
because you can't tlk about the past . . .
. . . when it hasn't happened yet.
Now, for SINCE.
We always - oops! - use 'since' with the present perfect,
and we usually mention the time or the date or an event
and the activity links to the present in some way.
so with 'since' you're always - well, mostly -
going to use the present perfect, simple or progressive
That's 'since' with the meaning of 'from a time'
not the other 'since' which means 'because'.
OK, now it's your turn.