Answer:
I am always in front of you, but yet I am never here. What am I?
I'm tall when I'm young and I'm short when I'm old. What am I?
I am a kind of coat that can only be put on when wet.
I start new then become old. Start clean but become dirty. I usually start big then become little. What am I?
What type of shoes do spies wear?
No matter how little or how much you use me, you change me every month.