#47 How to Use the Instrumental Case in Russian

When you want to say expressions such as “talk with a friend,” “write with a pen,” or “work as a doctor” in Russian, the form of the noun changes. For example, “with a friend” becomes с дру́гом, “with a pen” becomes ру́чкой, and “to work as a doctor” is expressed as рабо́тать врачо́м.

The case used in these expressions is the instrumental case, one of the six cases in Russian.

The instrumental case has a variety of functions. In addition to expressing instruments and means, it can indicate professions, positions, and roles. It is also used after certain verbs and prepositions.

In this article, I will explain what the instrumental case is, from its basic noun endings to its main uses, with example sentences.

1. Basics of the Instrumental Case

As its English name suggests, one of the main functions of the instrumental case is to indicate the “instrument” or “means” used to perform an action.

In the following sentence, ру́чка (pen) changes to the instrumental form ру́чкой.

• Я пишу́ ру́чкой.
  — I write with a pen.

Here, the instrumental case indicates the means by which the action is performed—in other words, what is used for writing.

In addition to instruments and means, the instrumental case is used after certain verbs and prepositions, in expressions of time, and to indicate the person or thing performing an action in passive constructions.

In the following sentence, друг (friend) changes to the instrumental form дру́гом. When combined with the preposition с, it means “with a friend.”

• Я говорю́ с дру́гом.
  — I am talking with a friend.

The instrumental case is also used to indicate a profession or role, as in “as a doctor.”

• Он рабо́тает врачо́м.
  — He works as a doctor.

As you can see, the instrumental case has several different functions. For this reason, I recommend learning its major uses separately, such as “instruments and means,” “people you do something with,” and “professions and roles.”

2. Instrumental Case Endings

In the instrumental case, masculine and neuter nouns generally take endings such as -ом / -ем, feminine nouns take -ой / -ей / -ью, and plural nouns take -ами / -ями.

I will first explain the basic patterns for masculine, feminine, neuter, and plural nouns.

Masculine Nouns: -ом / -ем

Masculine nouns ending in a consonant generally take -ом.

• стол → столо́м
  — table → with/by a table
• врач → врачо́м
  — doctor → as a doctor

Masculine nouns ending in -й or -ь may take -ем.

• геро́й → геро́ем
  — hero → as a hero
• учи́тель → учи́телем
  — teacher → as a teacher

However, the actual ending can vary depending on factors such as the final letter and stress, so you need to check the appropriate form for individual nouns.

Feminine Nouns: -ой / -ей / -ью

Feminine nouns ending in -а generally change to -ой.

• ма́ма → ма́мой
  — mother → with mother
• ру́чка → ру́чкой
  — pen → with a pen

Feminine nouns ending in -я generally take -ей.

• неде́ля → неде́лей
  — week → by/for a week
• Ма́рия → Ма́рией
  — Maria → with Maria

Feminine nouns ending in -ь take -ью.

• но́чь → но́чью
  — night → at night
• две́рь → две́рью
  — door → with/by a door

As you can see, with feminine nouns, you can generally determine the instrumental form by checking whether the noun ends in -а, -я, or -ь.

Neuter Nouns: -ом / -ем

Neuter nouns ending in -о generally change to -ом.

• окно́ → окно́м
  — window → with/by a window
• ме́сто → ме́стом
  — place → by/with a place

Neuter nouns ending in -е, on the other hand, generally take -ем.

• мо́ре → мо́рем
  — sea → by/with the sea
• по́ле → по́лем
  — field → by/with a field

Thus, the basic pattern for neuter nouns is -о → -ом and -е → -ем.

Plural Nouns: -ами / -ями

In the plural instrumental case, -ами or -ями is generally used.

• ма́мы → ма́мами
  — mothers → with the mothers
• учи́теля → учителя́ми
  — teachers → with the teachers / by the teachers

While instrumental endings differ considerably among masculine, feminine, and neuter nouns in the singular, plural forms are relatively straightforward, with -ами / -ями as the main endings.

However, some Russian nouns have irregular declensions. Rather than trying to memorize every exception from the beginning, I recommend starting with basic patterns such as стол → столо́м, ма́ма → ма́мой, and мо́ре → мо́рем.

3. Expressing Instruments and Means

One of the most common uses of the instrumental case is to indicate the instrument or means used to perform an action.

In the following sentences, каранда́ш (pencil) and нож (knife) change to their instrumental forms карандашо́м and ножо́м.

• Я пишу́ карандашо́м.
  — I write with a pencil.
• Она́ ре́жет хлеб ножо́м.
  — She cuts bread with a knife.

When you want to express what is used to perform an action, Russian generally places the noun representing the instrument in the instrumental case.

In English, you use the preposition with in expressions such as “write with a pencil” and “cut with a knife.” In Russian, the same relationship can be expressed simply by changing the noun itself to the instrumental case.

The instrumental case can also be used to express a means of transportation.

• Мы е́дем авто́бусом.
  — We are going by bus.
• Он е́дет по́ездом.
  — He is going by train.

By placing авто́бус (bus) or по́езд (train) in the instrumental case, you can indicate the means of transportation.

However, while the instrumental case can indicate the means of transportation itself, modern Russian also commonly uses “на + prepositional case,” as in на авто́бусе (by bus) and на по́езде (by train).

4. Expressing Professions and Roles

The instrumental case is also used to indicate a person’s profession, position, or role.

For example, when you use the verb рабо́тать (to work) to express “to work as ~,” the profession is placed in the instrumental case.

• Он рабо́тает врачо́м.
  — He works as a doctor.
• Она́ рабо́тает перево́дчиком.
  — She works as a translator.

In these examples, врач (doctor) and перево́дчик (translator) become врачо́м and перево́дчиком in the instrumental case. Here, the instrumental case indicates the profession or role in which the person works.

By contrast, when you simply state someone’s current profession with “X is a ~,” the nominative case is used.

• Он врач.
  — He is a doctor.
• Она́ перево́дчик.
  — She is a translator.

Both types of sentences describe professions, but their grammatical structures are different. When врач is in the nominative case, it establishes the relationship “subject = doctor.” With рабо́тать, however, the instrumental case emphasizes the role in which the person works: “as a doctor.”

In this way, the instrumental case can be used to express what role or capacity a person has when performing an activity.

5. Used with the Past and Future Forms of быть

The instrumental case is also commonly used with the past and future forms of быть (to be) when describing professions, positions, statuses, and similar characteristics.

When you say “He is a student” in the present tense, студе́нт (student) remains in the nominative case. Note that быть is normally omitted in the present tense.

• Он студе́нт.
  — He is a student.

When talking about the past and saying that someone “was” something, however, you use the past forms of быть—был / была́ / бы́ло / бы́ли—and nouns indicating professions, positions, and similar roles are generally placed in the instrumental case.

• Он был студе́нтом.
  — He was a student.
• Она́ была́ учи́тельницей.
  — She was a teacher.

Here, студе́нт → студе́нтом and учи́тельница → учи́тельницей, with both nouns changing to the instrumental case.

The instrumental case is also commonly used with the future forms of быть—бу́ду / бу́дешь / бу́дет / бу́дем / бу́дете / бу́дут—when expressing what someone will be.

• Он бу́дет врачо́м.
  — He will be a doctor.
• Она́ бу́дет учи́тельницей.
  — She will be a teacher.

The verb быть fundamentally describes the state of “being” something. If you want to express a clear change of state—“to become ~”— you can use стать (to become). A noun indicating a profession or role after стать is also placed in the instrumental case.

• Он стал врачо́м.
  — He became a doctor.
• Она́ ста́ла учи́тельницей.
  — She became a teacher.

Thus, when you simply state someone’s current profession or status, you generally use the nominative case. When expressing a profession, status, or state with the past or future forms of быть, the instrumental case is commonly used.

The basic pattern can be summarized as follows:

• Present: Nominative
  Он студе́нт.
  — He is a student.
• Past: Instrumental
  Он был студе́нтом.
  — He was a student.
• Future: Instrumental
  Он бу́дет студе́нтом.
  — He will be a student.

If you want to express the change of state itself, as in “to become a student,” you can use “стать + instrumental case.”

• Он ста́нет студе́нтом.
  — He will become a student.

6. The Instrumental Case Is Used with Certain Prepositions

The instrumental case is also used in combination with certain prepositions.

One of the most common is с. The structure “с + instrumental case” means “with” or “together with.”

• Я говорю́ с дру́гом.
  — I am talking with a friend.
• Она́ живёт с сестро́й.
  — She lives with her sister.
• Я иду́ в кино́ с друзья́ми.
  — I am going to the cinema with my friends.

The preposition с can be used not only with people but also to indicate that something is accompanied by or contains another item.

• Я пью чай с молоко́м.
  — I drink tea with milk.

Here, с молоко́м conveys the meaning “with milk.”

However, с is not the only preposition that takes the instrumental case. Several prepositions describing spatial relationships are also commonly used with it:

• над + instrumental: above / over
• под + instrumental: under / beneath
• пе́ред + instrumental: in front of
• за + instrumental: behind
• ме́жду + instrumental: between

These expressions can be used to indicate the position of a person or object.

However, some prepositions, such as под and за, can take cases other than the instrumental depending on their meaning. When they describe a stationary location, the instrumental case is used. When they indicate movement toward a destination, the accusative case is used instead.

• Кот сиди́т под столо́м.
  — The cat is sitting under the table. (Instrumental)
• Кот побежа́л под стол.
  — The cat ran under the table. (Accusative)

In the first sentence, стол becomes the instrumental столо́м because the sentence describes the cat’s location “under the table.” In the second sentence, стол is in the accusative because the sentence describes movement to a position under the table.

7. Expressing the Agent in Passive Sentences

The instrumental case can also indicate the person or thing that performs an action in a passive sentence.

In English, the agent in a passive construction is expressed with the preposition by. In Russian, the noun itself is generally placed in the instrumental case without a preposition.

I will compare an active and a passive sentence below.

• Active:
  Толсто́й написа́л рома́н.
  — Tolstoy wrote the novel.
• Passive:
  Рома́н был напи́сан То́лстым.
  — The novel was written by Tolstoy.

In the active sentence, Толсто́й (Tolstoy) performs the action and is therefore the subject, so it appears in the nominative case.

When the sentence is changed to the passive, рома́н (novel) becomes the subject, while Толсто́й, the person who performed the action, changes to the instrumental form То́лстым.

The agent expressed by the instrumental case does not necessarily have to be a person. The instrumental case can also be used when an object, natural phenomenon, or other force causes an action or effect.

The basic distinction between active and passive sentences can therefore be summarized as follows:

• Active sentence: agent = nominative case
• Passive sentence: agent = instrumental case

In this way, Russian uses the instrumental case to indicate who or what performs the action in a passive construction.

8. Summary

The instrumental case is one of the six cases in Russian and is used to express a wide range of meanings, including instruments, means, professions, and roles.

Its main functions can be summarized as follows:

When learning the instrumental case, it is important to focus not only on how noun endings change but also on why the instrumental case is being used in a particular sentence.

The instrumental case has many different functions, but by learning each one together with practical expressions and example sentences, you will gradually develop a clearer understanding of how it is used.

Yuri Miyajima

Writer

I’m a Japanese writer with a deep interest in Russia. Through my articles, I explore a wide range of topics related to the country, including its culture, history, traditions, food, everyday life, and language.