Грамматика русского языка. Часть 6. Падежи. Глава 6. Дательный падеж. Russian Grammar. Part 6. Cases. Unit 6. The Dative Case.

The principal meaning of the dative case is to or for. lt is used for the indirect obiect (the person or thing that is shown, told etc. something). The dative case also follows some common verbs, e.g. помогать (to help), звонить (to ring).

The dative case is needed for the indirect object of a sentence:

Subject +	Verb +	Object +	Indirect object
Vadim	gave	a bunch of roses	to Katya
Вадим	дал	букет роз	Кате

There are two endings for the dative singular of masculine nouns: у and ю.

Nominative singular	Translation	Dative singular
брат	brother	брату
Сергей	Sergei	Сергею
учитель	teacher	учителю

There are two endings for the dative singular of feminine nouns: е and и.

Nominative singular	Translation	Dative singular
сестра	sister	сестре
Катя	Katya	Кате
Мария	Maria	Марии

NB The two most common irregular dative feminine forms are for mother and daughter:
мать - матери and дочь - дочери.

There are two endings for the dative singular of neuter nouns: у and ю.

Nominative singular	Translation	Dative singular
окно	window	окну
море	sea	морю
здание	building	зданию

NB The neuter words время and имя form their dative singular as follows:
время – времени; имя – имени.

lf the indirect object of a sentence is plural then its ending must change to the dative plural; it must also change to the dative if the noun follows those verbs which always take the dative (e.g. помогать, to help, звонить, to ring and советовать, to advise).

The dative plural endings for nouns are the same for all genders. There are two possible endings (ам, or ям) and to determine which one should be used, look at the last letter of the nominative singular.

The ending for dative plural nouns ending in a consonant, а or o in the nominative singular is ам. Add this ending to nouns ending in a consonant; to nouns ending in a or o, remove the last letter of the nominative singular, then add ам, for example:
спортсмен – Врач советует спортсменам – The doctor advises the sportsmen.
сестра – Брат советует сёстрам – The brother advises (his) sisters.

The ending for dative plural nouns which end in anything else in the nominative singular (i.e. й, ь, я, ия, e, ие) is ям.
Remove the last letter of the nominative singular and add ям, for example:
герой – Президент дал героям медали – president gave medals to the heroes.
строитель – Банкир советует строителям – The banker advises the builders.

Nouns which have irregular nominative plurals form their dative plural from the nominative plural:

Nominative singular	Nominative plural	Dative singular
друг	друзья	друзьям
ребёнок	дети	детям
человек	люди	людям

The words дочь, время and имя form their dative plurals as follows:
дочь – дочерям, время – временам, имя – именам.