Answer:
I repeat only the last word you say. The more I repeat, the softer I got. I cannot be seen but can be heard. What am I?
Against the sun I protect your eyes and am often worn on the face of spies
The eight of us go forth not back to protect our king from a foe's attack. What are we?
You use me from your head to your toes. The more I work, the thinner I grow. What am I?
What is so delicate that saying its name breaks it?
Whoever made me don't want me. Whoever bought me don't need me. Whoever use me don't know me.