Learn Croatian: Otac dolazi po djecu u pet. - Father is coming to pick up the children at five.

In Croatian, the preposition po is often used with verbs of motion (like dolaziti, to come, or ići, to go) to mean "fetching" or "picking up" someone or something. So, dolazi po djecu literally means "comes for the children," but translates naturally as "comes to pick up the children."

Why is the word for children djecu here instead of djeca?

The preposition po requires the accusative case when it means "fetching" or "coming for." The word djeca (children) is a special collective noun that uses feminine singular endings, so its accusative form changes the -a to -u, becoming djecu.

Could I use the perfective verb dođe instead of dolazi?

Not here. Dolazi is an imperfective verb, which works perfectly for an action happening in the present or as an ongoing plan ("is coming"). Dođe is perfective (focusing on the completed action of arriving) and cannot be used for standard present-tense statements like this.

How do we know u pet means "at five" (o'clock)?