Same meaning, different case: the verbs that quietly change government
Diviti se and восхищаться mean the same thing, and a Russian speaker's instinct is to keep the case that already works. It doesn't transfer here - dative in one language, instrumental in the other - and it is not the only verb where a matching meaning hides a mismatched case.
Most of what makes Serbian cases hard for a Russian speaker is not the cases themselves - the inventory is nearly the same, minus the syncretism this blog has already covered - it is which case a given verb happens to demand. Two verbs can mean exactly the same thing, share half their letters, and still disagree about what to do with the noun standing next to them.
Where the government matches - which is why the trap stays quiet the rest of the time
It is worth naming a match before the mismatches, because the mismatches are memorable precisely because they are rare. Бојати се takes the genitive; so does бояться. Помагати takes the dative; so does помогать. Enough verbs agree that a Russian speaker builds, quite reasonably, a general expectation that a shared meaning comes with a shared case. That expectation is right often enough to be dangerous.
Admiration: dative against instrumental
Diviti se takes the dative - the thing admired sits in the same case as a gift's recipient. Восхищаться takes the instrumental - the same case a tool would take. Same feeling, same reflexive marking on both sides, and the noun standing next to the verb is grammatically doing two different jobs.
Диви се њеној храбрости.
He admires her courage.
Dative храбрости in Serbian where Russian needs the instrumental храбростью - the feeling translates word for word, the case does not.
Interest: a preposition where Russian has none
Интересоваться takes a bare instrumental, no preposition needed. Its Serbian counterpart, интересовати се, needs the preposition за plus the accusative - a structure closer to English's interested in than to its own Russian cousin.
Интересујем се за српску историју.
I'm interested in Serbian history.
За plus accusative in Serbian; Russian needs neither the preposition nor this case.
Laughing at someone: bare dative against a preposition
Смејати се некоме needs nothing but the bare dative - the person being laughed at simply stands there, no preposition attached. Russian routes the same idea through над plus the instrumental, the same preposition-and-case pair a physical object hovering over something else would need.
| Meaning | Serbian government | Russian government |
|---|---|---|
| дивити се | дативом | творительним |
| интересовати се | „за“ + акузативом | творительним, без предлога |
| смејати се | дативом | „над“ + творительним |
There is no rule that predicts which way a given verb will jump - reflexive-verb pairs, motion verbs and pairs where one language borrowed a preposition the other didn't all show up on this list for unrelated historical reasons. The only real defence is to learn each verb with its case attached from the first day, the way a dictionary entry does, rather than trusting the meaning to carry the grammar along with it.
None of these verbs is rare or advanced - admiration, interest and laughing at someone come up in ordinary conversation within the first few months of learning. That is exactly what makes the mismatch costly: a fluent-sounding sentence built entirely out of familiar words, wrong in the one place a dictionary lookup for the verb itself would not have caught.