Nouns: Instrumental Case

01

Using the Instrumental as a "Tool"

The most literal use of this case is to describe the instrument or means by which an action is done. In English, this is usually expressed with "by" or "with." In this context, no preposition is used; the ending of the noun simply changes.

• Jadę do pracy samochodem.

  I am going to work by car.

• Piszę list długopisem.

  I am writing a letter with a pen.

• Macham ręką.

  I am waving my hand (with my hand).

02

Identity and Professions

When using the verb być (to be) or zostać (to become) followed by a noun, that noun must be in the Instrumental case. This is standard for stating professions, nationalities, or relationships.

• Jestem studentem.

  I am a student.

• Ona jest inżynierem.

  She is an engineer.

• On chce zostać aktorem.

  He wants to become an actor.

Note that if you use to instead of a conjugated form of być, you do not use the Instrumental case (e.g., To jest lekarz). However, the standard "Subject + Verb + Noun" structure (On jest lekarzem) always requires the Instrumental.

03

Usage with Prepositions

The Instrumental case is required after specific prepositions. The most common is z (with), used to denote accompaniment.

• Idę do kina z bratem.

  I am going to the cinema with my brother.

• Piję kawę z mlekiem.

  I am drinking coffee with milk.

It is also used with prepositions describing static location:

• między (between)
• pod (under)
• nad (over/above)
• przed (in front of)
• za (behind)

• Kot śpi pod stołem.

  The cat is sleeping under the table.

• Samochód stoi przed domem.

  The car is standing in front of the house.

04

Usage with Specific Verbs

Certain verbs govern the Instrumental case even if they do not imply using a tool. The most common is interesować się (to be interested in).

• Interesuję się sportem.

  I am interested in sport.

• Ona interesuje się muzyką.

  She is interested in music.

05

Forming the Instrumental: Singular

Masculine and Neuter Nouns

Most masculine and neuter nouns take the ending -em. If the noun stem ends in k or g, an i is added, creating the ending -iem.

• dom (house) → domem

  house → with a house

• syn (son) → synem

  son → with a son

• okno (window) → oknem

  window → with a window

• Polak (Pole) → Polakiem

  a Pole → with a Pole

Feminine Nouns

Feminine nouns ending in -a change to -ą. This is a very consistent rule.

• kobieta (woman) → kobietą

  woman → with a woman

• woda (water) → wodą

  water → with water

• praca (work) → pracą

  work → with work

06

Forming the Instrumental: Plural

The plural form is very regular. Regardless of gender, the ending is almost always -ami.

• student (student) → studentami

  student → with students

• kobieta (woman) → kobietami

  woman → with women

• dziecko (child) → dziećmi (irregular stem change, but retains -mi)

  child → with children

07

Adjective Agreement

Adjectives must match the noun they modify.

• Masculine/Neuter Singular: The adjective ends in -ym or -im (after k/g).
• Feminine Singular: The adjective ends in -ą (rhyming with the noun).
• Plural (All genders): The adjective ends in -ymi or -imi.

• z dobrym kolegą

  with a good friend (masculine)

• z dobrą koleżanką

  with a good friend (feminine)

• z małymi psami

  with small dogs (plural)