Declension I (пе́рша відмі́на) is the largest noun class in Ukrainian: almost every noun ending in -а or -я belongs to it. That makes it mostly feminine (кни́га, земля́, пі́сня), but it also catches the male-denoting -а/-я nouns covered on the natural-gender page — Мико́ла, листоно́ша, and суддя́ all decline here even though they agree as masculine. This page gives the complete paradigm across all seven cases, singular and plural, for the hard subtype (кни́га), the soft subtype (земля́, пі́сня), and the masculine personal subtype (суддя́). The class is large but the difficulties are few: master the velar mutation, the genitive plural, and the -ою/-ею instrumental, and the rest is mechanical.
The hard subtype: кни́га
A "hard" Declension I noun has a stem ending in a hard consonant and takes -а. Here is кни́га "book" in full:
| Case | Singular | Plural |
|---|---|---|
| Nominative | кни́га | кни́ги |
| Genitive | кни́ги | книг |
| Dative | кни́зі | кни́гам |
| Accusative | кни́гу | кни́ги |
| Instrumental | кни́гою | кни́гами |
| Locative | (у) кни́зі | (у) кни́гах |
| Vocative | кни́го | кни́ги |
Three things in this table do real work. The dative and locative singular are кни́зі, not кни́гі — the г has mutated to з (more on this below). The genitive plural is bare книг with no ending. And the instrumental is -ою (кни́гою), a fuller ending than you might expect.
У ці́й кни́зі є́ ро́зділ, яки́й тобі́ то́чно сподо́бається.
There's a chapter in this book that you'll definitely like. (locative кни́зі — note the г→з mutation.)
Я подарува́ла йому́ кни́гу про істо́рію Ки́єва.
I gave him a book about the history of Kyiv. (accusative кни́гу.)
The velar mutation in the dative and locative
This is the first of the three big features. When a hard Declension I stem ends in a velar consonant — г, к, х — that consonant mutates before the dative/locative ending -і:
| Stem ends in | becomes | Example (nom → dat/loc) |
|---|---|---|
| г | з | нога́ → нозі́, кни́га → кни́зі |
| к | ц | рука́ → руці́, ріка́ → ріці́ |
| х | с | му́ха → му́сі, стрі́ха → стрі́сі |
This is not optional and not phonetic decoration — it is a fossilised sound change (the "second palatalisation") that every native speaker applies automatically. There is no logical shortcut: you simply learn the three pairs г→з, к→ц, х→с and apply them whenever a velar-stem -а noun goes into the dative or locative singular.
У ме́не боли́ть у нозі́ — здає́ться, я потягну́в м’яз.
My leg hurts — I think I've pulled a muscle. (locative нозі́, from нога́, г→з.)
Вона́ трима́ла в руці́ ма́леньку запи́ску.
She was holding a little note in her hand. (locative руці́, from рука́, к→ц.)
The soft subtype: земля́ and пі́сня
A "soft" Declension I noun has a soft stem and ends in -я. The endings are the soft-vowel counterparts of the hard ones: -і where the hard type has -и, -ею where it has -ою, and -ю in the accusative. Here are земля́ "land/earth" and пі́сня "song":
| Case | земля́ (sg) | земля́ (pl) | пі́сня (sg) | пі́сня (pl) |
|---|---|---|---|---|
| Nominative | земля́ | зе́млі | пі́сня | пісні́ |
| Genitive | землі́ | земе́ль | пі́сні | пісе́нь |
| Dative | землі́ | зе́млям | пі́сні | пісня́м |
| Accusative | зе́млю | зе́млі | пі́сню | пісні́ |
| Instrumental | земле́ю | зе́млями | пі́снею | пісня́ми |
| Locative | (на) землі́ | (на) зе́млях | (у) пі́сні | (у) пісня́х |
| Vocative | зе́мле | зе́млі | пі́сне | пісні́ |
Soft stems do not undergo the velar mutation — there are no velars at the end of a soft stem to mutate. So the soft type is in that respect simpler. But note the genitive plural: it is not a bare consonant but a form with a fleeting vowel plus -ь (земе́ль, пісе́нь) — covered next.
Пі́сля до́щу па́хне землі́, і ди́хати ле́гше.
After rain there's the smell of earth, and it's easier to breathe. (dative/locative землі́.)
Ця́ пі́сня нага́дує мені́ про дити́нство.
This song reminds me of my childhood. (nominative пі́сня.)
Він зна́є со́тні украї́нських пісе́нь напа́м’ять.
He knows hundreds of Ukrainian songs by heart. (genitive plural пісе́нь, with fleeting е.)
The genitive plural: zero ending, with surprises
This is the second big feature, and the one learners get wrong most often. Declension I has a zero ending in the genitive plural — you drop the -а/-я and what remains is the genitive plural form. With a simple stem, that gives a bare consonant cluster:
- кни́га → книг
- ка́рта → карт
- ха́та → хат
But when dropping the ending would leave an awkward final cluster, Ukrainian inserts a fleeting vowel (о or е) between the last two consonants, and a soft stem also adds -ь:
| Nominative singular | Genitive plural | What happened |
|---|---|---|
| земля́ | земе́ль | fleeting е inserted, soft -ь |
| пі́сня | пісе́нь | fleeting е inserted, soft -ь |
| ві́кна (n., for comparison) | ві́кон | fleeting о inserted |
| сестра́ | сесте́р | fleeting е inserted |
On top of that, some velar/о-stem nouns show the о → і alternation in this newly closed syllable, exactly the way стіл/стола́ works in Declension II:
- шко́ла → шкіл (о → і)
- гора́ → гір (о → і)
- доро́га → дорі́г (о → і)
У на́шому райо́ні відкри́ли вже́ кі́лька нови́х шкіл.
Several new schools have already opened in our district. (genitive plural шкіл, о→і.)
З цих гір ви́дно все́ мі́сто як на доло́ні.
From these mountains you can see the whole city laid out before you. (genitive plural гір, from гора́.)
The masculine personal subtype: суддя́
Male-denoting -а/-я nouns (суддя́ "judge," листоно́ша "letter-carrier," ста́роста "village head," Мико́ла) decline in Declension I just like feminine nouns of the same hardness — but, as the natural-gender page explains, they agree as masculine. Here is суддя́, a soft-stem masculine with the doubled дд (which is kept in every form):
| Case | Singular | Plural |
|---|---|---|
| Nominative | суддя́ | су́дді |
| Genitive | судді́ | су́ддів |
| Dative | судді́ | су́ддям |
| Accusative | суддю́ | су́ддів |
| Instrumental | судде́ю | су́ддями |
| Locative | (на) судді́ | (на) су́ддях |
| Vocative | су́ддя | су́дді |
Two things to notice. The genitive plural is су́ддів (ending -ів), not the zero ending — this is the regular pattern for masculine personal nouns, which pattern their genitive plural after Declension II masculines. And the accusative plural is су́ддів (= genitive), because суддя́ is animate.
Судді́ ви́несли ви́рок пі́сля двого́динної нара́ди.
The judges delivered the verdict after a two-hour deliberation. (nominative plural су́дді.)
Адвока́т зверну́вся до судді́ з прохання́м відкла́сти засі́дання.
The lawyer addressed the judge with a request to adjourn the session. (genitive/dative судді́.)
Мико́ло, переда́й, будь ла́ска, сіль!
Mykola, pass the salt, please! (vocative Мико́ло — masculine personal noun, vocative in -о.)
Be careful not to confuse this with male -о nouns: та́то and дя́дько denote males too, but they end in -о and therefore belong to Declension II, not here.
The whole class in one frame
| Hard (кни́га) | Soft (земля́) | |
|---|---|---|
| Gen. sg. | -и (кни́ги) | -і (землі́) |
| Dat./Loc. sg. | -і + velar mutation (кни́зі) | -і (землі́) |
| Acc. sg. | -у (кни́гу) | -ю (зе́млю) |
| Instr. sg. | -ою (кни́гою) | -ею (земле́ю) |
| Voc. sg. | -о (кни́го) | -е (зе́мле) |
| Gen. pl. | zero (книг) | zero + fleeting vowel + ь (земе́ль) |
| Dat./Instr./Loc. pl. | -ам / -ами / -ах | -ям / -ями / -ях |
Common Mistakes
❌ Я залиши́в окуля́ри на кни́гі.
Incorrect — velar mutation: the locative of кни́га is кни́зі (г→з), not *кни́гі.
✅ Я залиши́в окуля́ри на кни́зі.
I left my glasses on the book.
❌ Боли́ть у ногі́ / трима́ю в рукі́.
Incorrect — dative/locative mutate: у нозі́ (г→з), у руці́ (к→ц).
✅ Боли́ть у нозі́; трима́ю в руці́.
My leg hurts; I'm holding in my hand.
❌ кни́гой, земле́й (Russian-style -ой/-ей instrumental)
Incorrect — Ukrainian Declension I instrumental is -ою/-ею: кни́гою, земле́ю.
✅ кни́гою, земле́ю
with a book, with land — Ukrainian -ою/-ею.
❌ бага́то шко́л, п’ять гор (genitive plural without о→і)
Incorrect — these raise о to і in the genitive plural: бага́то шкіл, п’ять гір.
✅ бага́то шкіл, п’ять гір
many schools, five mountains.
❌ до́брий суддя́ declined with masculine -а case forms like ‘суддь’ (gen. pl.)
Incorrect — masculine personal -я nouns take -ів in the genitive plural: п’ять су́ддів, not a zero ending.
✅ На проце́сі було́ тро́є су́ддів.
There were three judges at the trial.
Key Takeaways
- Declension I is the -а/-я class — mostly feminine, plus the male-denoting суддя́/Мико́ла type that declines here but agrees as masculine.
- Three features carry the whole class: the velar mutation (кни́га → кни́зі, рука́ → руці́, му́ха → му́сі) in the dative/locative singular; the zero-ending genitive plural (книг, but земе́ль, шкіл, гір with fleeting vowels and о→і); and the -ою/-ею instrumental (кни́гою, земле́ю).
- The velar mutation is г→з, к→ц, х→с, and it strikes only the dative and locative singular of hard velar-stem nouns.
- Soft stems swap -и/-ою for -і/-ею and never mutate, but their genitive plural carries a fleeting vowel + ь (земе́ль, пісе́нь).
- Male -о nouns (та́то, дя́дько) are NOT here — they live in Declension II.
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- The Four DeclensionsA2 — Ukrainian sorts nouns into four declension classes by gender and ending — I (-а/-я, incl. male nouns like Мико́ла, суддя́), II (consonant/-й/-о, incl. ба́тько, та́то), III (feminine soft -ь), IV (the -ат-/-ен- extenders like теля, ім’я) — and within I and II a hard/soft/mixed stem split decides nearly every competing ending.
- Consonant Mutation in Declension (К/Ц, Г/З, Х/С)B1 — When a Ukrainian stem ends in a velar — к, г, х — and the case ending is the soft -і of the dative/locative singular (and certain plural and derived forms), the velar is forced to mutate: к→ц (рука́ → на руці́), г→з (нога́ → на нозі́), х→с (му́ха → му́сі); applying this automatically is one of the clearest markers of real competence.
- Declension II in Full (стіл, кінь, вікно́, по́ле)B1 — Declension II holds the masculine consonant-stem and neuter -о/-е nouns; it is where the о/і alternation (стіл→стола́), the genitive -а/-у split, the personal dative -ові/-еві (бра́тові), and the special locative -у (в саду́) all converge, while the neuters run a simpler course.
- Genitive Plural: FormsB1 — Ukrainian's hardest ending set, taught as a procedure: the zero ending for feminine -а/-я and neuter -о (often with a fleeting vowel — кни́га→книг, вікно́→ві́кон, сестра́→сесте́р), the -ів/-їв ending for masculines (стіл→столі́в, брат→браті́в), and -ей for soft-feminine -ь and many soft/hushing stems (ніч→ноче́й, кінь→коне́й), with the о/і alternation surfacing in zero-ending forms (нога́→ніг, гора́→гір, шко́ла→шкіл).
- Natural Gender and Common-Gender NounsB1 — For words denoting people, natural gender can override the ending's usual signal: та́то and дя́дько end in -о yet are masculine, суддя́ ends in -я yet is masculine, and common-gender nouns like сирота́ flip their agreement depending on whether the person is male or female.
- Hard, Soft, and Mixed Stem GroupsA2 — Almost every 'which ending?' question in Ukrainian noun declension reduces to one diagnosis: does the stem end in a hard consonant, a soft one, or a hushing ж/ч/ш/щ? Hard stems take о-endings (столо́м), soft stems take е-endings (коне́м), and mixed hushing stems pattern between them (ноже́м) — one three-way test that unlocks the whole case system.