Which tense to use after 'since'...

Cindy, the perfect is used in the main clause:

It has been two months since. . .

Contracted It + has:

It's been two months since. . .

Are you telling me that it's incorrect to say such things as 'It is two months since she arrived in NY'???
I read in a grammar book that we could use the present perfect after 'since' (as I said: 'It's (or 'it's been) two months since they have met', or things like that.) But somehow, some sentences sound strange to me... would my grammar book (quite a serious one, though) be wrong???

Dear teachers,

Is it true that we cannot use SINCE with the simple past except in clauses like:

It has been 2 months SINCE [she ARRIVED in NY.] = clause

but could we also say: "It has been 2 months SINCE she HAS ARRIVED in NY." ??

FOR, on the other hand, can be used with perfect and simple tenses, isn't that right?

Would you please give us some ex

Hello SCindy

You can say either:

'It's been 2 months since she arrived in NY' (i.e. 'it has been')

or:

'It's 2 months since she arrived in NY' (i.e. 'it is').

The first version puts more stress on the length of time.

Hello Hela

'It's been 2 months since she has arrived in NY' would not be correct.

'For' can indeed be

Would this sentence be correct?

The production brought the two celebrities together once again after a fifteen-year interval since "The Heat".

In this case, can I use after and since together?

I need an urgent reply.

Hello Fuat

Very tricky. This is the best I can do – others may have better versions:

'The production brought the two celebrities together for the first time since 'The Heat', some 15 years before.'

MrP

can I use "ago" instead of "before"?

By the way thank you very much.

My pleasure, Fuat.

'Ago' is usually used when we are counting back from the present moment. In a context such as yours, we don't know what the present moment is, so we have to use 'before' or 'previously.

MrP

Hello everyone,

when talking about past time is is true that we always have to use the simple present when we ask a question with "when" and the present perfect in a question with "how long"?

ex: a) When DID you GO to the cinema?
b) How long HAVE they STAYED under the bridge ?’ ‘For half an hour.’

Can we say: ‘How long DID they STAY under the bridge ?’

Hello Hela

Yes, all 3 are fine:

When did you go to the cinema?
How long have they stayed under the bridge?
How long did they stay under the bridge?

MrP