In short

By now you have met all seven cases one at a time. This lesson steps back and shows the system behind the endings: every Ukrainian noun belongs to one of four declensions (відміни), and each declension follows one master pattern. Two of those declensions — I and II — split further into a hard, soft, or mixed group (тверда, м’яка, мішана група), which only decides small spelling choices (-ою vs -ею, -ом vs -ем).

The good news: you do not memorise a new ending for every word. You identify the declension from gender + the nominative-singular ending, pick the group, and the whole paradigm follows.

The rule

Step 1 — find the declension. Look at the noun’s gender and its bare nominative-singular form:

• Declension I — nouns ending in -а / -я. Mostly feminine (кни́га, земля́), plus some masculine persons (Мико́ла, суддя́) and common-gender words.
• Declension II — masculine nouns with a zero ending (a bare consonant, or -й / -ь: стіл, кінь, край), the masculine nouns in -о (та́то, ба́тько), and neuter nouns in -о / -е / -я that do not grow a suffix (вікно́, мо́ре, життя́).
• Declension III — feminine nouns that end in a consonant (zero ending, often soft: ніч, сіль, ра́дість, любо́в), plus the irregular ма́ти.
• Declension IV — neuter nouns in -а / -я that grow the suffix -ат- / -ят- / -ен- in the oblique cases (теля́ → теля́ти, ім’я́ → і́мені).

The pair to watch is -я: земля́ is Declension I (feminine, no suffix growth), життя́ is Declension II (neuter, no growth), but теля́ is Declension IV (neuter, grows -ят-). Gender and suffix-growth tell them apart.

Step 2 — find the group (only for Declensions I and II):

• Hard (тверда) — the stem ends in a plain hard consonant (кни́га, стіл, вікно́).
• Soft (м’яка) — the stem ends in a soft consonant, shown by -ь, -й or an iotated vowel (пі́сня, кінь, край, мо́ре).
• Mixed (мішана) — the stem ends in a hissing consonant ж, ч, ш, щ (душа́, межа́, дощ, това́риш); a few masculines in -р (кобза́р, маля́р) also belong here.

The group is why душа́ takes -ею (душе́ю), not -ою, and why the soft/mixed masculine takes -ем (коне́м, доще́м), not -ом. Declensions III and IV have no groups — one pattern each.

Forms & patterns

The four declensions at a glance

The three groups (Declensions I & II)

Declension I — singular

Hard genitive ends in -и (кни́ги); soft and mixed in -і (пі́сні, душі́). Instrumental: hard -ою, but soft and mixed -ею (пі́снею, душе́ю). Dative/locative of кни́га shows the г→з change (кни́зі — see lesson 35). In душа́ the stress moves between stem and ending — mark it, do not level it.

Declension II — masculine, singular

Genitive singular is a meaning choice, not a group choice (see lesson 9): -а/-я for people, animals, trees, tools and measures (бра́та, коня́, ду́ба, ножа́, ти́жня — but рік takes ро́ку), -у/-ю for materials, collectives, abstractions, natural phenomena, buildings and institutions (піску́, са́ду, поря́дку, дощу́, ві́тру, мо́сту); a few nouns take either (стола́ or столу́), and the dative below is a separate choice. Instrumental: hard -ом (столо́м) vs soft/mixed -ем (коне́м, доще́м). The dative also appears as столу́ / коню́ / дощу́ (the -ові/-еві form is preferred for persons and animals). кінь is animate, so Acc = Gen (коня́); the inanimate стіл and дощ keep Acc = Nom. Notice the о→і alternation in the closed nominative syllable (стіл → стола́, кінь → коня́ — see lesson 38) and the stress shift back to the stem in the vocative (сто́ле).

Declension II — neuter, singular

Neuter nouns always have Acc = Nom. A soft-neuter subtype ends in -я with a lengthened consonant: життя́ (Gen життя́, Instr життя́м, Loc у житті́) — still Declension II, because it grows no suffix.

Declension III & IV — singular

Declension III instrumental takes -ю and usually doubles the final soft consonant (ні́ччю, and сі́ллю, по́дорожжю) — but not after a consonant cluster, where the -ю simply attaches (ра́дістю). Declension IV grows -ат-/-ят- (теля́ → теля́ти) or -ен- (ім’я́ → і́мені) in the genitive, dative and locative singular; the vocative repeats the nominative, and the instrumental of the -ят- type carries no suffix at all (теля́м, курча́м). The apostrophe of ім’я́ disappears once the я is gone (і́мені).

These tables show the singular — the one paradigm you need to identify the type; the plural has its own set of endings but is governed by the same declension.

Examples

Common mistakes

• столо́ю -> столо́м — a Declension II hard masculine takes instrumental -ом; -ою is the Declension I (feminine) ending.
• ко́нею -> коне́м — a soft masculine (II) takes -ем, not the feminine -ею.
• душо́ю -> душе́ю — after ж/ч/ш (mixed group) the Declension I instrumental is -ею, not -ою.
• у кни́гі -> у кни́зі — Declension I dative/locative changes г→з (also к→ц, х→с) before the ending -і.
• ні́чю -> ні́ччю — Declension III doubles the final soft consonant before instrumental -ю.
• з ра́дісті -> з ра́дістю — the Declension III instrumental ends in -ю (ра́дістю); -і is the genitive/dative form.
• немає теля́ -> немає теля́ти — a Declension IV noun grows -ят-/-ен- in the genitive, dative and locative singular.

Tips

• Two clues fix the declension every time: gender + nominative-singular ending. Run them in order and you rarely need to guess.
• The hard/soft/mixed split matters only for Declensions I and II — it decides tiny spelling choices (-ою vs -ею, -ом vs -ем). Declensions III and IV have no groups.
• Quick group test: hard = plain consonant before the ending; soft = -ь / -й / iotated ending; mixed = stem ends in a hissing ж, ч, ш, щ.
• The trap is -я: земля́ (I, feminine), життя́ (II, neuter, no growth) and теля́ (IV, neuter, grows -ят-) look alike — gender plus suffix-growth separate them.
• Declension III instrumental almost always doubles the consonant before -ю (ні́ччю, сі́ллю); the exceptions are a labial (любо́в’ю, with an apostrophe) or a consonant cluster (ра́дістю, plain -ю).
• Learn a handful of irregulars early: ма́ти (III → ма́тері) and the -ен- group ім’я́, пле́м’я (IV → і́мені, пле́мені).