9. "THERE USED TO BE" structure
USE
We use the structure "There used to be" to talk about something that existed in the past but does not exist now and vice versa.
(+) There used to be a lot of trees in the town.
(-) There didn't use to be many trees in the town.
(?) Did there use to be many trees in the town? (Yes, there did. / No, there didn't.)
(?) How many trees did there use to be in the town? (There used to be a lot of trees.)
Examples:
THERE USED TO BE or THERE WAS/WERE (Past Simple)
There were a lot of trees in the town.
There were a lot of trees in the town in the past. It is a fact. There can be a lot of trees now as well. But it is not important. We just want to say what was in the past.
There used to be a lot of trees in the town.
There were a lot of trees in the town in the past. But there aren't many trees in the town now. We want to emphasise the difference between the past and the present.
THERE USED TO BE and THERE IS/ARE (Present Simple)
Some years ago there didn't use to be so many trees in the town as there are now.
There were trees in the town in the past. But now there are much more trees.