Learn Farsi: بابا، کجا هستی؟

The verb ending tells you exactly who is doing the action. The -i at the end of hasti specifically means "you" (informal, singular). Because of this, you don't need to add the separate pronoun to (you) unless you really want to emphasize it.

Why is the full verb hasti used here instead of the short suffix form?

In Farsi, the verb "to be" has both short suffix forms and full forms like hasti. When talking about location or presence, such as asking where someone is, Farsi speakers almost always use the full form.

Where does the question word koja (where) belong in a sentence?

Unlike English, which puts question words at the very beginning, Farsi puts them where the answer would go. Since a location usually goes right before the verb at the end of a sentence, koja is placed directly before hasti.

Can I use pedar instead of baba?

baba is the familiar, everyday word for "dad." Farsi also has pedar for "father," which is more formal. Since this sentence uses the informal "you" verb hasti, using the casual baba fits the tone perfectly.