Using "their":
* Their house is on the corner.
* The students shared their ideas for the project.
* The birds built their nest in the tree.
* Their dog is very friendly.
* We enjoyed their company at the party.
Using "there":
* I left my keys there on the table.
* There are many beautiful flowers in the garden.
* Is anyone there?
* We went to the park, but there wasn't anyone there.
* There is a new restaurant opening downtown.
Using both "their" and "there":
* There were many people at their wedding.
* There is a big tree in their backyard.
* We found their car parked there in the driveway.
* They put their belongings there in the closet.
* The children are playing there in the sandbox.