Do you want your writing to be instantly transformed into a mucky mess of corporate and legalese-sounding jargony mush? Then be sure to use persons as the plural word for person. Whiz! Bang! You’ve got yourself something no one will want to read.
Today we usually only see persons in those kinds of behemoth documents. (Think about the Human Resources manuals you had to promise your boss you read.) It wasn’t always this way, though.
There is a difference between people and persons. Traditionally, persons was used when referring to a group of humans for which the exact number of humans was known.
Example: Four persons were involved in the robbery.
People was used as a mass noun when you didn’t know the number of humans in a group.
Example: There were so many people at the rally.
The words’ etymologies support this traditional usage. Person comes from the Latin word persona, meaning a singular “human being, person.” People comes from the Latin word populus, meaning “a people, nation; body of citizens; a multitude.”
When considering person’s etymology, it follows that plural word for multiple individuals should be persons. However, people has so taken over the definition of persons, in addition to its own, that now you really only see it in those stuffy Human Resources documents and legal writings I mentioned earlier.
So unless you’re a lawyer, or you’re writing a really boring piece of corporate text, use people.