Formal:
* 爸爸 (bàba): This is the most common and formal way to refer to your father. It's suitable for all situations, from speaking to your father directly to talking about him to others.
Informal:
* 爹 (diē): This is a more informal and traditional way to address your father. It's generally used in a familial setting.
* 爸 (bà): This is a shortened version of "爸爸" and is used more casually, often in a loving or playful way.
Other options:
* 父亲 (fùqīn): This is a more literary way to say "father" and is often used in written texts or formal speeches.
* 老爸 (lǎobà): This is a popular term for "dad" that means "old dad." It's generally used with a sense of affection.
Which one to use:
* When speaking to your father directly, "爸爸" is the most appropriate.
* When talking about your father to others, "爸爸" or "父亲" are both suitable.
* In informal settings with close family members, "爹" or "爸" might be used.
It's important to note that the choice of word can also reflect the speaker's age, region, and personal preferences.