Every thought or idea directs itself, at least ostensibly, towards two parts, a subject and predicate. The subject is the main focus of the idea. The subject is the main “actor” about which everything else is concerned.
The predicate is that, which is said about the subject. The predicate begins with the verb and includes the objects direct and indirect and most circumstantial happenings. Clauses are like sentences, that aren’t, however, ended but are joined to the main clause and describe attendant circumstances to add more meaning to the main clause, which is the sentence proper, indicating the main action of the subject.
The subject does the action in the “active” voice. It does the action for itself in the “middle” voice and it is the recipient of the action in the “passive” voice. But the subject remains the focus.
The “subject” is from the Latin, “sub,” “under” or “up to;” and “ject-” meaning, “thrown.”
“Predicate” is from “praedicare,” “to speak before,” meaning “to speak about.”
The sentence expresses an idea – complete in itself – that puts a subject and something about it.