Abstract
In some cases a predicate formed by a copulative verb být (to be) and a noun in nominative case may be expressed in two different agreement forms in past tense: that is either with the noun in position of a subject, or with the noun forming a verbo-nominal predicate. For an easier distinction of the grammar role of these nouns, especially in scholarly and journalistic texts, a noun in nominative case represents a subject and a noun in instrumental case represents a predicative noun.