I am in the sky but also in the ground. When you study me, no matter how long, I will always end with an F. I may be in your yard but not in your house. What am I?
Answer: A leaf.
This riddle appears in the following downloadable PDF files:
Can you solve one of the most famous logic puzzle ever?
Memory Matching game for kids, adults and seniors.
Connect the matching tiles and pop them all.