The sentence 'The dream of space travel became a reality' has the <em>subject</em> 'The dream of space travel', and a <em>linking verb</em> 'became', followed by <em>'a</em><em>reality</em>' that has the purpose of the adjective <em>'real'</em>. It became real/ It is real= It is a reality. <em>A predicate nominative or predicate noun renames the subject and completes a linking verb. A noun renames another noun.</em>
