Formal:
* "Votre père est-il..." (Is your father...) This is the most formal way to ask.
Informal:
* "Ton père est-il..." (Is your father...) This is the informal way to ask, used with friends or family.
* "Est-ce que ton père est..." (Is your father...) This is another informal option, which can be used in both spoken and written French.
To continue the question, you would need to add the rest of your question, for example:
* "Votre père est-il à la maison ?" (Is your father at home?)
* "Ton père est-il malade ?" (Is your father sick?)
Here are some other ways to ask about someone's father, depending on the context:
* "Quel est le métier de votre père ?" (What is your father's profession?)
* "Comment s'appelle votre père ?" (What is your father's name?)
Remember to use the correct form of "vous" or "tu" depending on the level of formality.