The Instrumental Case: With and By Means Of
The Instrumental case primarily indicates z kim or čim an action is performed, or pśez co. It is always used with a preposition (most commonly z - with) or after certain verbs, including the verb byś (to be) when describing someone's profession or state.
Nouns:
- Singular Masculine/Neuter: ending -om (hard) / -im (soft). (e.g., z bratom - with a brother, z wucabnikim - with a teacher, z městom - with a city, z pólom - with a field)
- Singular Feminine: ending -u (hard) / -u (soft). (e.g., z sotšu - with a sister, z zemju - with the earth)
- Plural (all genders): ending -ami (hard) / -ami (soft). (e.g., z bratšami - with brothers, z wucabnikami - with teachers, z sotšami - with sisters)
Adjectives:
- Singular Masculine/Neuter: ending -ym (hard) / -im (soft). (e.g., z dobrym bratom - with a good brother, z něžnim wucabnikim - with a tender teacher)
- Singular Feminine: ending -u (hard) / -u (soft). (e.g., z dobru sotšu - with a good sister, z něžnu žonu - with a tender woman)
- Plural (all genders): ending -ymi (hard) / -imi (soft). (e.g., z dobrymi bratšami - with good brothers, z něžnimi wucabnikami - with tender teachers)
Examples: Som z pśijaśelom (I am with a friend). Wóni rozmówaju z nami (They are talking with us). Pišom pśez wóźin (I am writing with a pen - literally 'through a pen'). Wóna dobra studentka (She is a good student - present tense of 'to be' omitted). Smy dobrymi studentami (We are good students - present tense of 'to be' omitted, Instrumental plural used).