Final answer:
When someone invites you to tutear, you would use the form 'tú' to talk to that person.
Step-by-step explanation:
When someone invites you to tutear, the form you would use to talk to that person is tú. In Spanish, tutear refers to using the informal second-person pronoun 'tú' instead of the formal 'usted' to address someone. It is used in more casual and familiar settings, such as among friends or family members.
Learn more about Spanish Pronouns