The instrumental case is called so because it is used to describe the instrument by which an action is performed.
Example:
есть суп ложкой – to eat soup with he spoon
резать ножом – to cut with a knife
ехать поездом – to go by train.
How to form instrumental case.
The instrumental case is formed from the nominative singular nouns with the help of the following endings:
– ом, – ем, ой, -ей, -ью( singular);
– ами, ями, (plural).
-by adding – ом to masculine nouns ending with a consonant (брат – братом) and neuter nouns ending in – o (окно – окном);
-by adding -ем to masculine nouns ending in -й, -ь (чай – чаем, учитель – учителем) and neuter nouns ending in -е (море – морем, орудие – орудием)
-by adding -ей to feminine and masculine nouns ending in -я (тётя – тётей, дядя – дядей).
-by adding -ой to feminine and masculine nouns ending in -а (вод – водой, папа – папой).
-by adding -ью to feminine nouns ending in -ь (ночь – ночью).
The usage of the Instrumental case.
Instrumental case questions: (с) кем?(with) who(m)? (с) чем? ( with) what?
1. Job, occupation.
Example:
мой сын хочет стать инженером – My son wants to become an engineer.
2. Hobby, interest.
Example:
Александра занимается спортом, увлекается танцами и интересуется русской культурой – Alexandra is doing gymnastics, is keen on dancing and she is interested in Russian culture.
3. After the word: доволен (to be satisfied with, to be pleased with).
Example:
мама очень довольна сыном – The mother is pleased with her son
Я довольна результатом – I am satisfied with the result.
4. Instrument of an action.
Example:
резать апельсин ножом – To cut an orange with the knife.
5. The meanings and manners of an action.
Example:
мы едем на пикник автобусом – We are going to pic nic by bus.
6. Seasons: times of the day.
Example:
осенью, зимой, весной, летом – in autumn, in winter, in spring, in summer.
Утром, днем, вечером, ночью – in the morning, in the afternoon, in the evening, at night.
Usage with some prepositions:
1. joint action.
Example:
вчера я ходила в кино с мужем – Yesterday I went to the cinema with my husband.
2. Congratulations.
Example:
С Днем Рождения! – Happy Birthday!
с Новым Годом! – Happy New Year!
С Пасхой! – Happy Easter!
3. after prepositions: над (above) ,под (under), перед (before, in front of) за (behind), между (between).
Example:
над дверью – above the door
под столом – under the table
за машиной – behind the car
между лекциями – between lectures.