1) When are they going to start treating me with some respect at work?
2) When are they starting treating me with some respect at work?
Are they both possible? Or we better avoid using the second one just not to have two verbs at the -ing form?
The second is unacceptable. Even "When are they starting to treat me ..?." is not natural. The present progressive is generally used to denote future arrangements. Thus, it's possible for the colleagues to meet to discuss their behaviour; one of them might conclude the meeting by saying: "OK, so its agreed - we're starting to treat her with some respect from tomorrow." However, it is highly unlikely that your particular question would be about an arrangement.
Thanks so much for the explanation![]()