Answer:
Some will use me, others not. Some have remembered, others forgot. For profit or gain, I'm used expertly. I can't be picked off the ground or tossed into the sea. What am I?
I have keys but no locks. I have space but no room. You can enter but canβt go outside. What am I?
My first part compliments people. My second part makes things known. My third part hurts feelings. My fourth part may hold a precious treasure. My fifth part is used when sharing fancy beverages.
Walk on the living, they donβt even mumble. Walk on the dead, they mutter and grumble. What are they?
When it comes to me, you go on red and stops on green. What am I?
What is full of holes but still holds water?