Every sentence have a subject and a predicate . Subject is the do or of an action.the simple subject of a sentence can be a noun,noun phrase or pronoun,and the simple predicate is a verb or verb phrase showing the action being done by the simplest subject.
In many grammar lessons,the predicate is often called just the verb or main verb.however it must have a subject and a tense that shows the time during .
Example: robert runs.
Subject =robert
Predicate =run