Explain the concept of a dependent clause.

A dependent clause, also known as a subordinate clause, is a group of words that contains a subject and a verb but cannot stand alone as a complete sentence. It relies on an independent clause to form a complete thought and convey a clear meaning.

Dependent clauses are called "dependent" because they depend on the main clause to provide context and complete their meaning. They function as adverbial, adjectival, or nominal clauses, modifying or adding information to the independent clause.

There are three types of dependent clauses: adverbial, adjectival, and nominal clauses.

1. Adverbial clauses: These clauses function as adverbs, modifying the verb in the independent clause. They answer questions such as when, where, why, how, or to what extent. For example:
- When the sun sets, we will go for a walk.
- She studied hard so that she could pass the exam.
In these examples, "when the sun sets" and "so that she could pass the exam" are adverbial clauses that provide additional information about the time and purpose of the actions in the independent clauses.

2. Adjectival clauses: These clauses function as adjectives, modifying nouns or pronouns in the independent clause. They provide more information about the noun or pronoun they are modifying. For example:
- The book that I borrowed from the library is very interesting.
- The girl who won the competition is my friend.
In these examples, "that I borrowed from the library" and "who won the competition" are adjectival clauses that describe the book and the girl, respectively.

3. Nominal clauses: These clauses function as nouns, acting as the subject, object, or complement in the independent clause. They can be introduced by words such as that, whether, if, or wh- words (who, what, when, where, why, how). For example:
- What she said surprised me.
- I don't know if he will come to the party.
In these examples, "what she said" and "if he will come to the party" are nominal clauses that act as the direct object and the object of the preposition, respectively.

It is important to note that dependent clauses cannot stand alone as complete sentences because they do not express a complete thought. They rely on an independent clause to provide the necessary information and context.