After as a preposition and conjunction
AFTER: DESPUES
After means ‘later than’ and ‘next in time or place’.
After can be used before a noun phrase (as a preposition):
Shall we have a swim after lunch?
The bank is just after the park, on the left.
After can introduce a clause (as a conjunction):
After I left him a message, he phoned me immediately.
She did voluntary work in a hospital after she graduated.
While or when?= MIENTRAS / CUANDO
While (or whilst) means ‘during the time when something else happens’. When can mean the same as while, but when can also refer to a point in time.
Compare
during the time something happens
|
a point in time
|
|
|
Since: time = DESDE
We use since to refer back to a previous point in time. We use since as a preposition with a date, a time or a noun phrase:
It was the band’s first live performance since May 1990. (since + date)
I have been happily married for 26 years, since the age of 21. (since + noun phrase)
We also use since as a conjunction to introduce a subordinate clause:
It’s so long since I saw them. (since + clause)
Lenny had slept most of the way since leaving Texas. (since + clause)
He’s been back to the office a few times since he retired. (since + clause)
Since and tenses
When since introduces an action or event at a point of time in the past, we can use the past simple or present perfect after since and the present perfect in the main clause:
They haven’t received any junk mail since they moved house.
They haven’t received any junk mail since they’ve moved house.
We can use the past simple, present perfect or past perfect after since with the expression it + be + time + since:
It’s been years since I rode a bike. (it’s = it has)
It’s been years since I’ve ridden a bike. (it’s = it has)
It’s years since I rode a bike. (it’s = it is)
It’s years since I’ve ridden a bike. (it’s = it is)
It’d been years since I’d ridden a bike. (it’d = it had)
BY THE TIME= PARA EL MOMENTO EN QUE ....
used for saying what has already happened at the time that something else happensBy the time we arrived, the other guests were already there.
ALREADY= YA
Already: meaning
We use already to emphasise that something was completed before something else happened. It is often used with the present perfect or past perfect:
The plane had already landed when the pilot announced that there would be a delay in getting to the gate.
Already is also used to show surprise about things that have happened or will have happened earlier than we expected.
