Meaning: be open and honest; reveal one's position or intentions.

Example: Shawn thought it was time to put his cards on the table and tell his friend that he had no intention of continuing with him in the partnership.

Meaning: be secretive or cautious, give nothing away.

Example: My brother don't know how much money his friends will spend this Friday night, he keep his card close to his chest.

Meaning: to have a secret advantage that is suddenly revealed to change the game. A hidden resource.

Example:
1. He did not just leave his house. He had a card up his sleeve that he did not even reveal to his family, which was his new flat in a posh locality.
2. The competition should always be checked for cards up their sleeves when you can.

Meaning: to be completed.

Example:
1. The work is almost entirely in the can if only he can convince the managing directors to give him a raise now.
2. His homework for the holidays is in the can although I cannot guarantee he will get the best grade this time.