Main Clauses are complete sentences that have a subject following a verb.
The Bear roars!
Subordinate Clauses rely on a main clause to be a complete sentence, they are composed of a subordinate conjunction following a subject following a verb.
As the meteors fall
These bad boys must begin with a relative pronoun. Relative pronouns are words like, who, whom, whose, which or even that! They may also start with a relative adverb, these badboys are words like when, where or why.
Who loves cucumbers?
Noun clauses are somewhat difficult to learn if you have no background, but if you have been speaking english all your life you have been using them your whole life! They simply are basically any clause that functions as a noun.