With citations of different authers, define Non-basic clause?

A non-basic clause is a clause that does not function as the main clause in a sentence and is dependent on another clause for its meaning. It typically provides additional information or clarification about the main clause.

According to Huddleston and Pullum (2002), non-basic clauses are subordinate clauses that are "dependent on some other element in the sentence." They explain that non-basic clauses can serve various functions, such as expressing time, reason, condition, or manner.

Quirk et al. (1985) define non-basic clauses as subordinate clauses that "do not stand alone as complete sentences but are dependent on main clauses for their meaning." They note that non-basic clauses can be introduced by subordinating conjunctions or relative pronouns.

In summary, non-basic clauses are subordinate clauses that provide additional information or clarification in a sentence and are dependent on the main clause for their meaning.