The following sentence is probably wrong, grammatically speaking, but I am sure that I hear this or a similar
expression from time to time. Does "new grammar" agree on this usage ?

"We have a conference rooms on the 5th floor. We'll talk IN there at 3pm."

(We have rooms / a room.)

What would be the objection? That "there" cannot be object of the preposition because its not a noun? I think "in there" and "out there" are common constructions in all the romance languages. Sorry I don't know what it's called. - A.

Edit. Maybe I'm wrong about that. Maybe other languages are more like "there within" and "there without." "In" and "out" are probably adverbs. Edit. edit. Yes, my dictionary lists "in" as an adverb. I'm thinking, "Throw out the garbage," "Take in the washing from the line."
Thanks, A
rooms/a room is simply a typo.

I had some lessons on English grammar in the past (LONG past), but now I barely remember any specifics.

What I remember is (sorry for not able to be more clear)

"you don't put a preposition in front of "there" and "here" (don't know the proper terminology in this context)"

You say "we'll talk THERE", NOT "we'll talk IN there".

Are these two "there's" different, grammatically?
Students: We have free audio pronunciation exercises.
We're in the same boat. I'm remembering some of it from 60 years ago. Many things which were called "bad English" then are okay now.

I'd say that both there's are the same. I think it would be rediculous to take this usage away from us. At this point, I'm looking at it as two adverbs, "Put the box there, inside."

The funny thing is that "out" is not a preposition, so when we say, "Put the box out there," we're not breaking the "no preposition before there" rule, although they sound exactly the same.

Edit. I give up! "He fell out the window" is a preposition!

Is that all you have to say, Clive?
- A.
Students: Are you brave enough to let our tutors analyse your pronunciation?
No, I also want to say 'Good-night'.
Pleasant dreams.
- A.