What is a noun clause? How is it structured?

A noun clause is a type of dependent clause that functions as a noun within a sentence. It can act as the subject, object, or complement of a verb, or as the object of a preposition.

The structure of a noun clause typically consists of a subordinating conjunction followed by a subject and a verb. The subordinating conjunction introduces the clause and connects it to the main clause. Some common subordinating conjunctions used to introduce noun clauses include "that," "whether," "if," "why," "how," and "what."

For example:
- Subject: "What he said" surprised me. ("What he said" acts as the subject of the verb "surprised.")
- Object: She knows "that he is coming." ("That he is coming" acts as the object of the verb "knows.")
- Complement: My goal is "to learn Spanish." ("To learn Spanish" acts as the complement of the verb "is.")
- Object of preposition: I am interested in "what she said." ("What she said" acts as the object of the preposition "in.")

Noun clauses can also be introduced by question words such as "who," "whom," "whose," "which," and "where." These question words can function as the subject or object of a verb, or as the object of a preposition.

Overall, noun clauses play an important role in sentence structure by functioning as nouns and providing essential information within a sentence.