This question already has an answer here:
After watching this video with the following examples:
- I appreciate your coming here.
- He resents Marry's being promoted.
- I am tired of Migel's complaining.
I do not understand why in this exercise (on the last page) they wrote:
- We sat and watched the girls dancing.
- We sat and watched the girls' dancing.
Can somebody explain me which variant is the correct one and why?