The verb быть is also used in sentences with predicate adjectives. You may recall that in copular sentences (“to be” type sentences), the subject is the thing you are talking about. The predicate is everything else:

There are two types of adjectives in Russian: long form adjectives, which are the vast majority of adjectives, and short form adjectives.

An adjective that is in the predicate is, not surprisingly, called a predicate adjective. Long form predicate adjectives in Russian normally occur in the instrumental case. The only exception is when it is directly a part of a present tense is/am/are phrase, in which case the predicate is in the nominative case:

A short form adjective in the predicate will always be in the nominative case:

Of course feminine, neuter, and plural forms are also possible: