Please dear teachers,
Can you help me with this?
Which of the sentences has the right use of relative pronouns? And why?
1. I know several cases when people have complained about the new restaurant.
2. I know several cases in which people have complained about the new restaurant.
3. I know several cases where people have complained about the new restaurant.
Which is the right relative pronoun?
And, is it defining or non-defining?
Thanks to you all.