Final answer:
The correct pronoun to use when talking to your father in Spanish is tú.
Step-by-step explanation:
The correct pronoun to use when you are talking to your father in Spanish is tú.
Tú is the informal second-person singular pronoun, used when speaking to someone who you are familiar with, like a family member, friend, or peer.
For example, you could say '¿Cómo estás, tú?' (How are you?) when talking to your father.
Learn more about Spanish pronouns