Formal:
* He/She/They/It: These are the standard pronouns for third person singular and plural.
* The individual/The person/The entity/The subject: These are more general and neutral terms.
* Mr./Ms./Mx./Dr./Professor [Last Name]: These are formal titles used with names.
Informal:
* He/She/They/It: These are also common in informal settings.
* That guy/That girl/Those people: These are more casual and less formal.
* The dude/The chick/The folks: These are very informal and might be considered slang.
* [Name]: In very casual settings, you might simply use the person's name.
Other considerations:
* Gender: When referring to someone whose gender you don't know, it's best to use "they" or "them" to avoid making assumptions.
* Context: The way you refer to a third person will depend on the context of the conversation or writing. For example, in a formal academic paper, you would use more formal language than in a casual conversation with friends.
* Respect: It's important to be respectful when referring to others. Avoid using language that is derogatory or offensive.
Examples:
* Formal: "The individual in question has been identified."
* Informal: "That dude over there looks really nervous."
Ultimately, the best way to refer to a third person depends on the specific situation and your own personal style.