Sir, <br/><br/>The word that follow "to be verb" is complement of verb or complement of subject exam <br/><br/><br/>1. I am a teacher. <br/><br/>a teacher= verb complement or subject complement. <br/><br/>2. To see is to believe. <br/><br/> here "to believe" = verb complement or subject complement. <br/><br/><br/>Thanks.