1. Used to indicate being together or being involved. Example:
I ordered a sandwich with a drink.
He was with his friend when he saw me.
2. Used to indicate "having". Example:
I met a guy with green eyes.
Were you the one talking with an accent?
People with a lot of money are not always happy.

3. Used to indicate "using"Example:
I wrote a letter with the pen you gave me.
This is the soup that I made with rice and barley.