ABSTRACT
The instrumental case of nouns is made from the genitive singular without its ending. So, vowel changes present in the genitive singular, e.g. loss of penultimate e or changes from ó to o or o to q, recur here (pies: ps-a gives psem/psami; wróg: wrog-a gives wrogem/wrogami; gaLAI: gaLCz-i gives gaLCziA/gaLCziami).
