One clause is one simple sentence, i.e. one S – P /Subject – Predicate/ group.
I. CLAUSAL CONSTITUENTS
The English clause is made up of five major constituents: S V O C A / Subject - Verb/ Predicate – Object – Complement – Adverbial modifier /. The main parts are the S and V /traditionally marked by V/. O and C are secondary sentence constituents closely associated with the V, while A is more peripheral.
Most current linguistic theories are verbo-centric, i.e. the V is taken as central hub/ pivot/ of the expression determining the whole pattern of the clause. Thus the type of V determines the type of clause pattern.