dad
In French, 'papa' is the most common way to say 'dad'. It can be used both as a term of address (when speaking to one's father) and as a term of reference (when speaking about one's father to others). Like in English, it is a very informal term, typically used in family contexts or between close friends.
Dad, you are my hero.
This is a simple, direct statement that is commonly used by children who admire their fathers, just like in English. In French, 'tu es' is the verb 'to be' and 'mon héros' means 'my hero'.
Dad was cooking last night.
This sentence is in the imperfect tense, which is generally used to describe past events that are viewed as completed. 'Cuisinait' is the imperfect form of the verb 'cuisiner', which means 'to cook'.
I have to call dad.
This sentence states a requirement or obligation. 'Je dois' translates directly to 'I have to'; 'appeler' means 'call'. In this sentence, 'papa' is the object of the verb 'call'.