* -ly: This creates an adverb, meaning "in a legal way." For example: "legally binding."
* -ize: This creates a verb meaning "to make legal." For example: "to legalize marijuana."
* -ity: This creates a noun meaning "the state of being legal." For example: "legality of the agreement."
Other less common suffixes could be:
* -ism: This could be used to refer to a specific legal system or doctrine. For example: "legalism"
* -ist: This could be used to describe someone who specializes in law. For example: "legalist"
The best suffix to use will depend on the specific context.