Family

The Instrumental Case: With and By Means Of

The Instrumental case primarily indicates with whom or with what an action is performed, or by means of what. It is always used with a preposition (most commonly с - with) or after certain verbs, including the verb быть (to be) when describing someone's profession or state.

• Nouns:

  • Singular Masculine/Neuter: ending -ом (hard) / -ем (soft) / -ём (stressed soft) / -ем (after vowel). (e.g., с братом - with a brother, с учителем - with a teacher, с мужем - with a husband, с го́родом - with a city, с по́лем - with a field)
  • Singular Feminine: ending -ой (hard) / -ей (soft) / -ёй (stressed soft). (e.g., с сестро́й - with a sister, с зе́млей - with the earth, с ма́терью - with a mother)
  • Plural (all genders): ending -ами (hard) / -ями (soft). (e.g., с братья́ми - with brothers, с учи́телями - with teachers, с сёстрами - with sisters)

• Adjectives:

  • Singular Masculine/Neuter: ending -ым (hard) / -им (soft). (e.g., с до́брым бра́том - with a good brother, с си́ним учи́телем - with a blue teacher)
  • Singular Feminine: ending -ой (hard) / -ей (soft) / -ёй (stressed soft). (e.g., с до́брой сестро́й - with a good sister, с си́ней же́нщиной - with a blue woman)
  • Plural (all genders): ending -ыми (hard) / -ими (soft). (e.g., с до́брыми братья́ми - with good brothers, с си́ними учи́телями - with blue teachers)

• Examples: Я иду́ с дру́гом (I am going with a friend). Они́ разгова́ривают с на́ми (They are talking with us). Я пишу́ ру́чкой (I am writing with a pen). Она́ хоро́шая студе́нтка (She is a good student - present tense of 'to be' omitted). Мы хоро́шие студе́нты (We are good students - present tense of 'to be' omitted).