There are 7 grammatical cases in Ukrainian. We need them to show the relationship between words in a sentence. Grammatical cases apply to nouns, pronouns, adjectives, and numerals.

Ukrainian, unlike English, doesn’t have a fixed word order. You can move the words around without changing the core meaning of a sentence, though this works best with short, simple sentences.

Example:
Хло́пець чита́є кни́гу
Кни́гу чита́є хло́пець
Чита́є хло́пець кни́гу

All of these mean “A boy reads a book“. However, the first sentence (Хлопець читає книгу), which follows the subject–verb–object (SVO) order, sounds the most natural and neutral.
Different word orders are used when you want to emphasize a certain part of the sentence, for example, to highlight the object or the action.

If you try to do the same thing in English, the sentence usually changes its meaning, for example, “A book reads a boy” no longer means the same thing. The closest English parallel is with pronouns, where word order still matters: “He sees her”, “Her sees he”, and “Sees her he”,  but only the first one is grammatical in English.

By changing the ending of the word “книга” to “книгу” you know that “книгу” is the object of the sentence (accusative case). The endings can vary depending on the declension type the noun belongs to. There are 4 declension types, and all nouns in the same group follow the same pattern. Almost all nouns ending in “а” in the nominative case belong to the first declension type.

This is a general overview of Ukrainian grammatical cases. In later lessons, you will learn which case to use and what ending to choose.

Case (відмі́нок) Function
(фу́нкція)
Question
(запита́ння)
Запита́ння
(question)
Еxample (при́клад)
Nominative
(називни́й)
a subject of a verb who?
what?
хто?
що?
ді́вчина чита́є
(a girl reads)
Genitive
(родови́й)
a relationship or
possession
whose?
from what?
what of?
кого́?
чого́?
кни́га ді́вчини
(a girl’s book)
Dative
(дава́льний)
an indirect object of a verb whom?
what?
ко́му?
чо́му?
подару́нок ді́вчині
(a gift to a girl)
Accusative
(знахі́дний)
a direct object whom?
what?
кого́?
чого́?
він ба́чить ді́вчину́
(he sees a girl)
Instrumental
(ору́дний)
a means or tool used or companion present in/while performing an action with who?
with what?
ким?
чим?
ро́змова з ді́вчиною
(conversation with a girl)
Locative
(місце́вий)
a location (physical or temporal) on / in whom?
on / in what?
на ко́му?
на чо́му?
на ді́вчині капелю́х
(a hat on a girl)
Vocative
(кли́чний)
a direct address -* -* ді́вчино, де ти?
Girl, where are you?
* it is used to address directly a person, an animal or an object.

Some examples:

Продаве́ць продає́ футбо́лку ді́вчині. The seller sells a T-shirt to a girl.

Продаве́ць (nominative).
This is the subject of the sentence,  the person performing the action. In Ukrainian, the subject is usually in the nominative case.

Футбо́лка → Футбо́лку (accusative)
This is the direct object, the thing being sold. In Ukrainian, direct objects typically take the accusative case.

Ді́вчина → ді́вчині (dative).
This is the indirect object, the person receiving the item. In Ukrainian, recipients of an action are in the dative case. 


Це футбо́лка продавця́. – This is the seller’s T-shirt.

Футбо́лка (nominative)
This is the subject of the sentence.

Продаве́ць → продавця́ (genitive)
The genitive case is used to show possession or belonging, in English, this corresponds to 's or of. Here, продавця́ (from продаве́ць) means "of the seller".


Я пишу́ ру́чкою.I write with a pen.

Я (nominative)
The subject of the sentence, the one doing the writing.

Ру́чка → Ру́чкою (instrumental)
The instrumental case shows the means or tool used to perform an action, here, the pen, I write by means of a pen.


Су́мка в маши́ні.The bag is in the car.

Су́мка (nominative)
The subject of the sentence,  what we’re talking about (the bag).

Маши́на(в) маши́ні (locative)
The locative case is used after certain prepositions (like в/у, на, по) to show location, where something or someone is. Here: “in the car.” The nominative form маши́на changes to маши́ні in the locative.


Note: Some words of foreign origin never change their endings:

Вона́ чита́є меню́ в кафе́. She reads the menu at the cafe.

Вона́ (nominative)
Меню́ (nominative) = Меню́ (accusative)
Кафе́ (nominative) = Кафе́ (locative)