1. This tire is not on the truck. It’s off. It’s off the truck.

(The preposition "off" is often used with verbs and other prepositions such as "of.")

tractor wheel

 2. His jacket is off.

He’s taking off his hat.

(The "verb" take is often used with "off" when clothes are removed from the body.)

tuxedo

 3. The lights are off.

("Off" is used as an adjective in this sentence.)

off switch

 4. She’s talking right now, but soon she’ll be off the phone.

on the phone
 5. This airplane is off the ground.
airplane

 6. His shoes are off his feet.

His shoes are off.

bare feet

 7. The dog jumped up on the table, but he must get off.

(The verb "get" is often used with "off": get off the bus; get off the plane; get off the train; get off the elevator. )

dog on table

 8. He’s taking some cheeseburgers off the grill.

(take off = remove)

man barbequing

 9. I got this recipe for Vietnamese-style spring rolls off the internet.

(You get information "off the internet" or "from the internet.")

spring rolls

 10. He’s working right now, but in a few hours this police officer will be off duty.

(off = not working)

police officer