What are the different types of noun clauses? Explain each type with examples.

Noun clauses are dependent clauses that function as nouns within a sentence. They can act as subjects, objects, or complements. There are several types of noun clauses, each serving a different grammatical function. Let's explore each type with examples:

1. Subject Noun Clauses:
Subject noun clauses act as the subject of a sentence. They answer the question "What is the subject doing?" or "What is happening?" Examples include:
- What he said surprised everyone.
- Whether she will attend the party is still uncertain.
- That he won the competition was unexpected.

2. Object Noun Clauses:
Object noun clauses function as the direct object, indirect object, or object of a preposition within a sentence. They answer the question "What is the subject doing to something?" or "What is the subject receiving?" Examples include:
- She asked where the nearest library is.
- They wonder if they should go on vacation.
- He gave whoever needed help a hand.

3. Complement Noun Clauses:
Complement noun clauses act as the complement of a verb or a linking verb. They provide additional information about the subject or the object. Examples include:
- Her only wish is that she could travel the world.
- The fact that he arrived late disappointed everyone.
- The question is whether we should proceed with the plan.

4. Appositive Noun Clauses:
Appositive noun clauses provide further explanation or clarification about a noun or pronoun in the sentence. They are set off by commas and can be removed without changing the meaning of the sentence. Examples include:
- My goal, to become a doctor, requires years of study.
- The rumor, that they were getting married, spread quickly.
- His belief, that honesty is the best policy, guided his actions.

5. Nominal Relative Clauses:
Nominal relative clauses function as nouns and are introduced by relative pronouns such as "who," "whom," "whose," "which," or "that." They can act as subjects, objects, or complements. Examples include:
- I don't know who will be attending the meeting.
- She is looking for a book that explains quantum physics.
- The person whom I met yesterday is a famous actor.

In conclusion, noun clauses come in various forms and serve different purposes within a sentence. They can act as subjects, objects, complements, appositives, or nominal relative clauses. Understanding these different types of noun clauses is essential for mastering English grammar.