Complex Sentences – contains one main or independent clause and one + subordinate or dependent clauses

            When a dependent clause stands alone, it creates a fragment.

            A fragment is less than one main clause

            It is a major error that  an academic writer should avoid.

CAUTION:

            Some subordinate connectives double function as prepostitions

Although they are both modifiers, it is easy to distinguish one from the other

A dependent clause always has a subordinate connective that is followed by a   complete subject and complete verb

EX Before the Hawaiian lei came into being, necklaces and crowns were worn as body adornments, tokens of love, and symbol of rank since prehistoric times.