Iii. выделите в предложениях ing-формы, выпишите и определите, являются ли они причастием, герундием или отглагольным существительным:
1. chalk is used for writing on the blackboard.
2. we sat by the river-side listening to the running of the water.
3. the cleaning of the room was done by the girls.
4. working in the garden is very good for the health of people.
5. going home from the cinema, they were discussing the play they had seen.
6. remembering that time was like going back to his childhood.

Объяснение:

1. Chalk is used for writing on the blackboard.   writing герундий

2. We sat by the river-side listening to the running of the water.  listening  причастие

3. The cleaning of the room was done by the girls.  cleaning отглагольное существительное

4. Working in the garden is very good for the health of people.  Working герундий

5. Going home from the cinema, they were discussing the play they had seen.  

Going причастие              were discussing   verb in past continious

6. Remembering that time was like going back to his childhood.  Remembering   герундий