Answer:
My first half is normally made of stone, my second is crazy, and I taste sweet when complete.
What does a WW1 Trench, A Submarine and a Popular Phone App all have in common?
If I have it, I don't share it. If I share it, I don't have it. What is it?
What word looks the same upside down and backwards?
Always old, sometimes new. Never sad, sometimes blue. Never empty, sometimes full. Never pushes, always pulls.
What is so fragile that saying its name breaks it?
Difficult
Animal
Easy
Food
Funny
Kids
Logic
What am I?