What is a sentence?
A SENTENCE is an IDEA complete in itself.
A SENTENCE is a SUBJECT and PREDICATE.
A sentence is an idea complete in itself, which is made up of two notions, a subject and predicate.
An idea comprises two notions. In Grammar the idea is the sentence and the two notions are the subject and predicate.
A sentence is a subject (someone or something) and predicate (what is said about it).
In the sentence “Joe Bloggs buys a drink,” “Joe Bloggs” is the subject, and “buys a drink” is the predicate.
The word, “sentence,” comes from the Latin “sententia,” meaning, “thought.” The word, “predicate,” comes ultimately from the Latin, “praedicare,” meaning, “to fore-speak,” meaning, “to speak about.”
A sentence, which is an idea complete in itself, is also a “clause.” A clause possesses a subject and predicate but it may or may not be a sentence, for, where a sentence must be an idea complete in itself, a clause may be an idea not complete in itself, thus not a sentence.
A clause may be a subordinate clause, beginning with a conjunction, so, not a sentence.