Instrumental: Forms

The instrumental (instrumental) is the case of the tool you act with and the company you keep — the case behind pišem olovkom ("I write with a pencil") and idem s prijateljem ("I go with a friend"). Its endings are mostly painless: the plural is shared with the dative and locative, so you already know it, and the only real decision in the singular is one familiar fork — hard stems take -om, soft (palatal) stems take -em. This page lays out the full paradigm and that one spelling rule; the next page handles when to use it.

The singular: the -om / -em fork

For masculine and neuter nouns, the instrumental singular ending is -om after a hard stem and -em after a soft (palatal) stem. This is the very same hard/soft logic you have already met in the genitive plural and elsewhere — the language simply will not put a back vowel like -o directly after a palatal consonant, so it switches to the front vowel -e.

The feminine -a declension does not face the fork at all — it takes -om across the board (ženom, knjigom, vodom), and unlike in the dative, the k/g/h nouns do not soften here, because the ending begins with -o, not -i: it stays rukom, knjigom, nogom.

The palatal stems that trigger -em

A stem counts as soft (palatal) when it ends in one of these consonants:

č, ć, đ, dž, š, ž, j, lj, nj, c

After any of these, the instrumental singular ending switches from -om to -em. Run through the high-frequency cases:

A note on doublets

The soft-stem rule has some genuine wobble. Several masculine nouns are listed in dictionaries with both endings — putem and (older/regional) putom, kraljem and rarely kraljom. The standard, safe choice after a palatal is always -em, and that is what you should produce. Where a doublet exists it is a matter of style, not of right and wrong; modern standard Croatian leans on -em after palatals.

The i-type feminine: -i, -ju, and jotation

The i-declension feminine nouns (those that end in a consonant in the nominative: noć, stvar, ljubav, kost, sol) have the messiest instrumental in the language. There are two competing forms:

• the plain -i form, identical to the genitive/dative/locative singular: noći, stvari, riječi;
• the -ju form, which fuses the -j of the ending with the final stem consonant (a process called jotation): ljubav → ljubavlju, krv → krvlju, sol → solju, kost → košću.

In the jotated form, a stem-final v picks up an l (ljubav → ljubavlju, krv → krvlju), a final st turns to šć (kost → košću, radost → radošću), and a final l gives lj (sol → solju). The -i form is always grammatically available and is the lower-risk choice when you are unsure; the -ju form is more frequent in fixed and slightly elevated expressions (svom snagom, s ljubavlju, s velikim oduševljenjem).

The plural: -ima and -ama — and it's free

Here is the labour-saving news. The instrumental plural is identical to the dative and locative plural — the famous three-way merger of the Croatian oblique plural. You learned these forms for the dative; they cost nothing more here.

The split is the same as in the dative: feminine -a nouns take -ama, everything else takes -ima (and the i-type feminines side with the masculines and neuters — stvarima, not *stvarama). And, as in the dative plural, the k/g/h softening does not happen, because the ending begins with -a: rukama, knjigama, nogama keep their stems intact.

How this differs from English

English has no instrumental case and no morphological way to mark "with what" or "with whom" — it leans entirely on the single preposition with plus an unchanged noun. Croatian instead changes the noun itself (olovka → olovkom) and, crucially, distinguishes the tool from the company by the presence or absence of a preposition, not by the ending. So where English says "with a pencil" and "with a friend" identically, Croatian says olovkom (bare, no preposition) but s prijateljem (with the preposition s). The forms on this page are only half the story; the means-and-accompaniment page explains the s contrast that English speakers reliably get wrong.

Common Mistakes

Key Takeaways

• The instrumental singular for masculine/neuter is -om after hard stems and -em after soft (palatal) stems — the same hard/soft fork found across the language.
• The soft consonants that trigger -em are č ć đ dž š ž j lj nj c (so nožem, ključem, prijateljem, morem, poljem).
• Feminine -a nouns always take -om (ženom, knjigom, rukom) — no k/g/h softening here.
• Feminine i-type nouns have -i (always safe) or a jotated -ju (ljubavlju, solju, košću) in fixed expressions.
• The plural is -ima for everything except feminine -a nouns, which take -ama — and it is identical to the dative/locative plural, so you already knew it.