A noun clause is a subordinate clause that is used as a noun. Examples: "That the band had to cancel its concert disappointed many fans." [subject]/ "Ed's duties at the shop are not what he had expected." [predicate nominative]
Independent clauses and Subordinate clauses help make up noun clauses. "An Independent clause: expresses a complete thought and can stand by itself as a sentence." Examples: "They discovered some usually large footprints."
"A Subordinate clause: does not express a complete thought and cannot stand by itself as a sentence." Examples: "what we need to repair first" A subordinate clause can also be known as a dependent clause.
A noun clause may be used as a subject, a predicate nominative, a direct object, an indirect object, or an an object of a preposition. Examples: "That Marie Curie changed modern science is well known." [Subject]
Sometimes, the introductory word in a noun clause is excluded but understood. Example: " I believe their new address is 6541 spring street." [That is understood]