General usage:
* The juvenile delinquent was sentenced to community service.
* The book was aimed at a juvenile audience.
* The judge dismissed the case, ruling that the defendant was juvenile.
Figurative/Idiom usage:
* The actor's performance was juvenile and lacked depth.
* The argument was juvenile and lacked any substance.
* Her attempts to flirt were juvenile and awkward.
The word "juvenile" can have a slightly negative connotation, so it's important to be mindful of the context and your intended meaning when using it.