As a noun:
* I love to spread jam on my toast in the morning.
* The band played a jam session late into the night.
* The traffic was so bad, we were stuck in a jam for hours.
* My fingers are jammed after playing the piano for so long.
As a verb:
* I jammed my finger in the door.
* The mechanic jammed the new part into the engine.
* He jammed on his guitar, improvising a bluesy solo.
* The protesters jammed the streets, blocking traffic.
As an adjective:
* The car was jammed packed with people.
* The party was jam-packed and full of energy.
In an idiom:
* He's in a jam after forgetting his passport.
* I'm really jammed for time right now.
These are just a few examples, and the specific usage of "jam" will depend on the context of your sentence.