Question

1. Most of us never ask ourselves if and how television might hurting us.

2. Most never ask themselves if and how television might hurting them.

3. Most never ask themselves if and how television might hurting us.
.....
Which ones are grammatically correct?

Answer 1

All three need to say, "might BE hurting us". Otherwise, all are correct.

Answer 2

One could also say, "how television hurts us." "hurting" is a gerund, a noun. A verb is needed.