What is the incantation for the spell that creates a Patronus?

What is the incantation for the spell that creates a Patronus? The incantation is “Expecto Patronum.”

In the Harry Potter series, the words summon the Patronus Charm, a defensive spell that produces a protective magical guardian. A witch or wizard normally casts it by concentrating intensely on a happy or positive memory. A successful Patronus can appear as a silvery animal whose form is individual to the caster; Harry Potter’s is a stag.

Professor Remus Lupin teaches Harry the charm in Harry Potter and the Prisoner of Azkaban because a Patronus is one of the most effective defenses against Dementors. Those creatures feed on happiness and hope, so the spell’s positive emotional focus is part of its magic rather than merely a pronunciation exercise.

The alternatives describe different spells. Stupefy is a stunning spell, Accio summons objects, and Lumos produces light. “Expecto Patronum” is the incantation, while “Patronus Charm” is the name of the spell itself.