As a preposition:
* The cat is sleeping inside the basket.
* I left my keys inside the car.
* It's warm and cozy inside the house.
As an adjective:
* The inside of the box was empty.
* The inside story of the scandal was finally revealed.
* I'm not sure what's going on inside her head.
As an adverb:
* Let's go inside and get out of the rain.
* It's dark inside, but I can see a light.
* Can you hear me inside?
As part of a phrase:
* The inside track on the latest gossip.
* An inside job.
* Turn inside out.
The best way to use "inside" depends on the specific context and meaning you want to convey.