Declining "Tko" (Who)
The interrogative pronoun tko (who) changes its form depending on its grammatical role.
| Case | Form | Meaning |
|---|
| Genitive / Accusative | koga | whom / of whom |
| Dative / Locative | kome | to whom / about whom |
| Instrumental | kim | with whom |
Use koga for direct objects (Accusative) or when a verb requires the Genitive case.
Use kome for recipients (Dative) or with Locative prepositions like o (about).
Use kim (almost always with the preposition s or sa) to ask "with whom" an action is done.
Declining "Što" (What)
When asking about objects, topics, or events, što (what) follows a similar pattern. Its Accusative form is identical to the Nominative (što).
| Case | Form | Meaning |
|---|
| Genitive | čega | of what |
| Dative / Locative | čemu | to what / about what |
| Instrumental | čime | with what |
Certain verbs, like bojati se (to be afraid), require the Genitive case, so you will use čega.
Use the Locative form čemu with prepositions like o (about). You will also see it used in the Dative when expressing what someone is reacting to (e.g., laughing at something).
Use the Instrumental form čime to ask what someone is using, doing, or fascinated by. When referring to objects or means, the preposition s is usually omitted.