Answer:
I am a protector. I sit on a bridge. One person can see right through me while others wonder what I hide.
I go inside boots and outside shoes. What am I?
What is cut on a table but is never eaten?
I am lighter than air, but a hundred people cannot lift me. Careful, I am fragile. What am I?
I begin and have no end. Eventually I will be the end of all that has begun.
The answer I give is yes, but what I mean is no. What was the question?