"The predicative is the significant part of the compound nominal
predicate. It can be expressed in different ways:
1. By a noun in the common case, occasionally by a noun in the
She is a pretty child. (Galsworthy)
The book is my sister’s.
In Russian the predicative is expressed either by a noun in the
nominative case or by a noun in the instrumental case.
Он был учителем.
2. By an adjective.
He’s awfully dear and unselfish. (Galsworthy)"