Answer:
I turn around once. What is out will not get in. I turn around again. What is in will not get out.
I am in the past never in the future. I don't exist but have existed. I saw what you saw and that is what I will ever see.
I go around a yard but does not move.
I plow and plow, but never sow. What am I?
The 8 of us go forth and not back to protect our king from a foe's attack. What am I?
I am your mother's brother's only brother in law. Who am I?