Learn Hardcore Croatian: Ivan je u gradu.

Je is the third-person singular present tense form of the verb biti (to be). It functions as the copula “is,” linking the subject Ivan with the location expressed by u gradu.

Why is grad written as gradu here instead of grad?

The preposition u (“in”) requires the noun that follows it to be in the locative case when describing a static location. The locative singular of grad (“city”) is gradu, so u gradu literally means “in the city.”

How do I know when to use the locative case or another case after the preposition u?

In Croatian, u can govern either the locative or the accusative case:

Use the locative to indicate a static location (answering “Where?”): je u gradu (“is in the city”).
Use the accusative to indicate motion toward a place (answering “Where to?”): e.g. ide u grad (“is going to the city”).

Why are there no articles like “the” or “a” before gradu?

Croatian does not have definite or indefinite articles. Nouns stand alone without “the” or “a,” and meaning is conveyed through context and case endings.

Can I change the word order to U gradu je Ivan? Does word order matter?

Croatian has a relatively flexible word order for emphasis and nuance.

Ivan je u gradu is the neutral order.
U gradu je Ivan shifts the focus onto the location (in the city) rather than on Ivan.

Is it necessary to include Ivan, or could you say On je u gradu or even just Je u gradu?

You can replace Ivan with the pronoun on (“he”): On je u gradu (“He is in the city”).
Croatian is a pro-drop language, so if context is clear you can even say Je u gradu, though that’s less common without prior context.
In everyday speech you usually include either the noun or pronoun to keep the sentence clear.

I’ve seen u grad in other sentences. What’s the difference between u gradu and u grad?

u gradu (locative) means “in the city” (static location).
u grad (accusative) means “into the city” (motion toward the city).
Which form you choose depends on whether you’re talking about being somewhere or moving somewhere.

Why is Ivan not inflected like gradu?

Ivan is the subject of the sentence and remains in the nominative case (subjects are nominative). Only the noun governed by the preposition u changes to the locative here. Nominative nouns typically keep their base form, so Ivan stays unchanged.