Understanding Subordinate Clauses: Definition, Usage, and Examples

Subordinate clauses are a fundamental building block of complex sentences, allowing for the expression of nuanced relationships between ideas. Mastering their use is crucial for both effective writing and comprehension.

This article provides a comprehensive guide to subordinate clauses, covering their definition, structure, types, and usage rules. Whether you’re a student, writer, or simply looking to improve your English grammar, this guide will equip you with the knowledge and practice you need to confidently use subordinate clauses.

This article is designed for English language learners of all levels, from intermediate to advanced. It will be particularly helpful for those preparing for standardized tests, writing academic papers, or simply aiming to communicate more effectively in English.

By the end of this article, you’ll be able to identify, analyze, and use subordinate clauses with accuracy and confidence.

Table of Contents

• Definition of a Subordinate Clause
• Structural Breakdown
• Types of Subordinate Clauses
  • Noun Clauses
  • Adjective Clauses (Relative Clauses)
  • Adverb Clauses
• Examples of Subordinate Clauses
  • Noun Clause Examples
  • Adjective Clause Examples
  • Adverb Clause Examples
• Usage Rules
• Common Mistakes
• Practice Exercises
  • Exercise 1: Identifying Subordinate Clauses
  • Exercise 2: Completing Sentences with Subordinate Clauses
  • Exercise 3: Correcting Errors in Subordinate Clauses
• Advanced Topics
  • Elliptical Clauses
  • Embedded Clauses
• Frequently Asked Questions
• Conclusion

Definition of a Subordinate Clause

A subordinate clause, also known as a dependent clause, is a clause that cannot stand alone as a complete sentence. It depends on a main clause (also known as an independent clause) to form a complete thought. Think of it as a piece of a sentence that needs another piece to make sense. Subordinate clauses provide additional information, context, or detail to the main clause.

Unlike a main clause, which expresses a complete thought and can stand alone as a sentence, a subordinate clause begins with a subordinating conjunction (e.g., because, although, if, when, since) or a relative pronoun (e.g., who, which, that, whom, whose). These words connect the subordinate clause to the main clause and indicate the relationship between them.

Subordinate clauses function as nouns, adjectives, or adverbs within the larger sentence. This functional role determines the type of subordinate clause.

For example, a subordinate clause acting as a noun is called a noun clause, while one modifying a noun is called an adjective clause (or relative clause), and one modifying a verb, adjective, or adverb is called an adverb clause.

Structural Breakdown

The structure of a subordinate clause typically consists of the following elements:

1. Subordinating Conjunction or Relative Pronoun: This word introduces the clause and connects it to the main clause. Examples include because, if, when, that, who, which.
2. Subject: The noun or pronoun that performs the action or is described in the clause.
3. Verb: The action or state of being in the clause.
4. Optional Complements: These include objects, complements, and modifiers that provide additional information about the subject or verb.

The order of these elements can sometimes vary, especially in questions or when certain elements are emphasized. However, the presence of a subordinating conjunction or relative pronoun is a defining characteristic of a subordinate clause.

Here’s a simple example to illustrate the structure:

Because it was raining, we stayed inside.

In this example:

• Because is the subordinating conjunction.
• It is the subject.
• Was raining is the verb.

Types of Subordinate Clauses

Subordinate clauses are classified into three main types based on their function within the sentence: noun clauses, adjective clauses (relative clauses), and adverb clauses. Each type plays a distinct role in providing information and adding complexity to sentences.

Noun Clauses

A noun clause functions as a noun within the main clause. It can act as a subject, object, complement, or appositive. Noun clauses are often introduced by words like that, what, who, whom, which, whoever, whomever, whichever, whether, if, how, when, where, why.

For example:

What he said surprised everyone.

In this sentence, the noun clause “What he said” acts as the subject of the verb “surprised.”

Adjective Clauses (Relative Clauses)

An adjective clause, also known as a relative clause, modifies a noun or pronoun in the main clause. It provides additional information about the noun it modifies. Adjective clauses are typically introduced by relative pronouns (who, whom, which, that, whose) or relative adverbs (where, when, why).

For example:

The book that I borrowed from the library is very interesting.

In this sentence, the adjective clause “that I borrowed from the library” modifies the noun “book.”

Adverb Clauses

An adverb clause modifies a verb, adjective, or adverb in the main clause. It provides information about time, place, reason, manner, condition, concession, purpose, or result. Adverb clauses are introduced by subordinating conjunctions such as because, although, if, when, since, while, before, after, until, unless, as, so that, in order that, where, wherever.

For example:

Because it was raining, we stayed inside.

In this sentence, the adverb clause “Because it was raining” modifies the verb “stayed” and provides the reason for staying inside.

Examples of Subordinate Clauses

To further illustrate the different types of subordinate clauses, here are several examples organized by category. These examples will help you to identify and understand how each type of clause functions within a sentence.

Noun Clause Examples

The following table provides examples of noun clauses functioning as different parts of a sentence, such as subject, object, complement, and appositive. Understanding these different functions will help you to recognize noun clauses in various contexts.

Function	Example Sentence	Noun Clause
Subject	What she said was surprising.	What she said
Subject	How he did it remains a mystery.	How he did it
Subject	Whether he will come is uncertain.	Whether he will come
Direct Object	I don’t know what he wants.	what he wants
Direct Object	She told me that she was tired.	that she was tired
Direct Object	They announced who had won the prize.	who had won the prize
Indirect Object	Give whoever needs it a blanket.	whoever needs it
Predicate Nominative (Complement)	The problem is that we don’t have enough time.	that we don’t have enough time
Predicate Nominative (Complement)	My belief is that everyone deserves a chance.	that everyone deserves a chance
Appositive	The rumor that he is leaving is false.	that he is leaving
Appositive	The question whether we should go is still being debated.	whether we should go
Subject Complement	This is what I’ve been waiting for.	what I’ve been waiting for
Subject Complement	The issue is how we can resolve this problem.	how we can resolve this problem
Object of a Preposition	I am worried about what might happen.	what might happen
Object of a Preposition	Pay attention to what the teacher says.	what the teacher says
Object of a Preposition	He is interested in how the brain works.	how the brain works
Delayed Subject	It is not clear why she left.	why she left
Delayed Subject	It is important that everyone participates.	that everyone participates
Direct Object	I wonder if he will be on time.	if he will be on time
Subject	What you do is your responsibility.	what you do

As shown in the table above, noun clauses can take on various roles within a sentence. Recognizing these roles will improve your understanding of sentence structure and grammar.

Adjective Clause Examples

Adjective clauses, also known as relative clauses, modify nouns or pronouns, providing additional information. The following table contains examples of adjective clauses introduced by relative pronouns (who, whom, which, that, whose) and relative adverbs (where, when, why).

Relative Pronoun/Adverb	Example Sentence	Adjective Clause	Noun Modified
who	The man who helped me is my neighbor.	who helped me	man
who	She is the artist who painted this portrait.	who painted this portrait	artist
whom	The person whom I saw was very tall.	whom I saw	person
whom	The candidate whom the committee selected is highly qualified.	whom the committee selected	candidate
which	The car which I bought is very reliable.	which I bought	car
which	The book which she recommended was excellent.	which she recommended	book
that	The movie that we watched was boring.	that we watched	movie
that	The song that he wrote became a hit.	that he wrote	song
whose	The student whose essay won received a prize.	whose essay won	student
whose	The author whose book I read is very talented.	whose book I read	author
where	The restaurant where we ate was excellent.	where we ate	restaurant
where	This is the town where I grew up.	where I grew up	town
when	I remember the day when we first met.	when we first met	day
when	The time when she arrived was quite late.	when she arrived	time
why	I don’t know the reason why she left.	why she left	reason
that	The idea that she proposed was innovative.	that she proposed	idea
which	The house, which had a large garden, was perfect for them.	which had a large garden	house
who	My sister, who is a doctor, works at the local hospital.	who is a doctor	sister
whose	The company, whose profits have increased, is expanding.	whose profits have increased	company
where	The park, where we often go for walks, is beautiful.	where we often go for walks	park

Adjective clauses add detail and specificity to sentences, making them more informative and engaging. They are essential for creating vivid descriptions and providing context.

Adverb Clause Examples

Adverb clauses modify verbs, adjectives, or adverbs, providing information about time, place, reason, manner, condition, concession, purpose, or result. The following table provides examples of adverb clauses introduced by various subordinating conjunctions.

Subordinating Conjunction	Type	Example Sentence	Adverb Clause
because	Reason	Because it was raining, we stayed inside.	Because it was raining
since	Reason	Since he was tired, he went to bed early.	Since he was tired
as	Reason	As it was getting late, we decided to leave.	As it was getting late
if	Condition	If it rains, we will cancel the picnic.	If it rains
unless	Condition	Unless you hurry, you will miss the bus.	Unless you hurry
when	Time	When I finish work, I will go to the gym.	When I finish work
while	Time	While I was walking, I saw a friend.	While I was walking
before	Time	Before you leave, please close the windows.	Before you leave
after	Time	After the movie ends, we will go for dinner.	After the movie ends
until	Time	We will wait until the rain stops.	until the rain stops
although	Concession	Although it was difficult, she succeeded.	Although it was difficult
though	Concession	Though he was nervous, he gave a great speech.	Though he was nervous
even though	Concession	Even though it was expensive, I bought it.	Even though it was expensive
where	Place	Where there’s a will, there’s a way.	Where there’s a will
wherever	Place	Wherever you go, I will follow you.	Wherever you go
as	Manner	Do as I say.	as I say
so that	Purpose	He studied hard so that he could pass the exam.	so that he could pass the exam
in order that	Purpose	She exercised regularly in order that she would stay healthy.	in order that she would stay healthy
as…as	Comparison	He is not as tall as his brother.	as tall as his brother
than	Comparison	She is smarter than I thought.	than I thought

Adverb clauses add depth and context to sentences, providing essential details about when, where, why, and how actions occur. They are critical for expressing complex ideas and relationships.

Usage Rules

When using subordinate clauses, it’s important to follow certain rules to ensure grammatical correctness and clarity:

1. Punctuation: Use a comma to separate a subordinate clause from the main clause when the subordinate clause comes before the main clause. If the subordinate clause comes after the main clause and is essential to the meaning of the sentence, a comma is generally not needed.
2. Subject-Verb Agreement: The verb in the subordinate clause must agree with its subject in number and person.
3. Tense Consistency: Maintain consistent verb tenses between the main clause and the subordinate clause, particularly when describing events that occur at different times.
4. Pronoun Agreement: Pronouns within the subordinate clause must agree in number and gender with the nouns they refer to.
5. Correct Subordinating Conjunctions/Relative Pronouns: Use the appropriate subordinating conjunction or relative pronoun to accurately convey the intended relationship between the clauses.

Here are some examples illustrating these rules:

• Correct: Because it was raining, we stayed inside. (Comma used because the adverb clause comes first)
• Correct: We stayed inside because it was raining. (No comma needed because the adverb clause comes last and is essential)
• Incorrect: We stayed inside, because it was raining. (Comma is sometimes optional if the reason is an afterthought, but generally omitted if essential)
• Correct: The book that I read was interesting. (Relative pronoun “that” correctly introduces the adjective clause)
• Incorrect: The book who I read was interesting. (Incorrect relative pronoun)

Common Mistakes

One of the most common mistakes is using a comma incorrectly. Remember, if the subordinate clause comes before the main clause, use a comma.

If it comes after and is essential to the sentence’s meaning, generally no comma is needed.

Another mistake is using the incorrect subordinating conjunction or relative pronoun. Make sure the word you choose accurately reflects the relationship you want to convey.

Additionally, ensure that your verb tenses are consistent and that your pronouns agree with their referents.

The following table illustrates some common mistakes and their corrections:

Incorrect	Correct	Explanation
Because it rained, I stayed home.	Because it was raining, I stayed home.	Adding “was” clarifies the continuous action.
The book, that I read, was good.	The book that I read was good.	Unnecessary commas removed; the clause is restrictive.
I like the person who’s car is red.	I like the person whose car is red.	Correct use of “whose” to show possession.
Although he is tired, but he kept working.	Although he is tired, he kept working. OR He is tired, but he kept working.	Do not use “but” after “although.”
If I would have known, I would have helped.	If I had known, I would have helped.	Correct conditional tense usage.
She asked could I help her.	She asked if I could help her.	Use “if” or “whether” to introduce an indirect question.
I don’t know where is he.	I don’t know where he is.	Correct word order in indirect questions.
He said that he will come.	He said that he would come.	Consistent past tense usage after “said”.
The reason is because I was late.	The reason is that I was late. OR I was late because…	Avoid redundant “reason is because.”
Who did you see? The man who I gave the book to.	Who did you see? The man to whom I gave the book.	Formal, correct usage of “to whom.” (Less common in modern English, “who I gave the book to” is often acceptable).

Practice Exercises

The following exercises will help you practice identifying and using subordinate clauses correctly. Each exercise focuses on a different aspect of subordinate clauses, from identification to sentence construction and error correction.

Exercise 1: Identifying Subordinate Clauses

Identify the subordinate clause in each of the following sentences. Indicate whether it is a noun clause, adjective clause, or adverb clause.

No.	Sentence	Subordinate Clause	Type
1	Because it was cold, I wore a jacket.
2	The book that I borrowed is very interesting.
3	What he said surprised everyone.
4	If it rains, we will stay home.
5	I don’t know what she wants.
6	The house where I live is very old.
7	Although he was tired, he kept working.
8	She told me that she was going to the store.
9	The man who helped me is my neighbor.
10	Since you are here, you can help me.

Answer Key:

No.	Sentence	Subordinate Clause	Type
1	Because it was cold, I wore a jacket.	Because it was cold	Adverb Clause
2	The book that I borrowed is very interesting.	that I borrowed	Adjective Clause
3	What he said surprised everyone.	What he said	Noun Clause
4	If it rains, we will stay home.	If it rains	Adverb Clause
5	I don’t know what she wants.	what she wants	Noun Clause
6	The house where I live is very old.	where I live	Adjective Clause
7	Although he was tired, he kept working.	Although he was tired	Adverb Clause
8	She told me that she was going to the store.	that she was going to the store	Noun Clause
9	The man who helped me is my neighbor.	who helped me	Adjective Clause
10	Since you are here, you can help me.	Since you are here	Adverb Clause

Exercise 2: Completing Sentences with Subordinate Clauses

Complete the following sentences by adding an appropriate subordinate clause. Indicate the type of subordinate clause you added.

No.	Sentence	Type of Clause
1	I will go to the party __________.
2	The movie __________ was very entertaining.
3	She didn’t know __________.
4	__________ , he decided to stay home.
5	The gift __________ was very thoughtful.
6	I will call you __________.
7	__________ is a mystery to me.
8	He succeeded __________ .
9	The city __________ is beautiful.
10	__________ , the game will be cancelled.

Possible Answer Key:

No.	Sentence	Type of Clause
1	I will go to the party if I have time.	Adverb Clause
2	The movie that we watched last night was very entertaining.	Adjective Clause
3	She didn’t know what to do.	Noun Clause
4	Because he was tired, he decided to stay home.	Adverb Clause
5	The gift that she gave me was very thoughtful.	Adjective Clause
6	I will call you when I arrive.	Adverb Clause
7	Why she left is a mystery to me.	Noun Clause
8	He succeeded because he worked hard.	Adverb Clause
9	The city where I live is beautiful.	Adjective Clause
10	If it rains, the game will be cancelled.	Adverb Clause

Exercise 3: Correcting Errors in Subordinate Clauses

Identify and correct the errors in the following sentences related to subordinate clauses.

No.	Incorrect Sentence	Corrected Sentence
1	Because it rained, I stayed home.
2	The book, that I read, was good.
3	Although he is tired, but he kept working.
4	If I would have known, I would have helped.
5	She asked could I help her.
6	I don’t know where is he.
7	He said that he will come.
8	The reason is because I was late.
9	I like the person who’s car is red.
10	Who did you see? The man who I gave the book to.

Answer Key:

No.	Incorrect Sentence	Corrected Sentence
1	Because it rained, I stayed home.	Because it was raining, I stayed home.
2	The book, that I read, was good.	The book that I read was good.
3	Although he is tired, but he kept working.	Although he is tired, he kept working.
4	If I would have known, I would have helped.	If I had known, I would have helped.
5	She asked could I help her.	She asked if I could help her.
6	I don’t know where is he.	I don’t know where he is.
7	He said that he will come.	He said that he would come.
8	The reason is because I was late.	The reason is that I was late.
9	I like the person who’s car is red.	I like the person whose car is red.
10	Who did you see? The man who I gave the book to.	Who did you see? The man to whom I gave the book.

Advanced Topics

For advanced learners, understanding elliptical clauses and embedded clauses can further enhance your grasp of subordinate clauses and sentence structure.

Elliptical Clauses

Elliptical clauses are subordinate clauses in which some words have been omitted because they are understood from the context. This omission often occurs in adverb clauses, where the subject and auxiliary verb are left out when they are the same as in the main clause.

For example:

While walking, I saw a friend.

Here, “While walking” is an elliptical clause. The full clause would be “While I was walking,” but “I was” has been omitted because it’s understood from the main clause.

More Examples:

• When possible, close all the windows. (When it is possible)
• If necessary, call me. (If it is necessary)
• He is taller than I am. (Often shortened to: He is taller than me)

Embedded Clauses

Embedded clauses are subordinate clauses that are nested within another clause. This creates a more complex and layered sentence structure. Embedded clauses can function as nouns, adjectives, or adverbs.

For example:

The book that I told you about is on the table.

In this sentence, “that I told you about” is an adjective clause modifying “book.” The main clause is “The book is on the table.” The adjective clause is embedded within the main clause.

More Examples:

• I know that you believe he is innocent. (Noun clause “that you believe he is innocent” contains the noun clause “he is innocent.”)
• The man who said he saw the accident is a reliable witness. (Adjective clause “who said he saw the accident” contains the noun clause “he saw the accident.”)
• She left because she thought he didn’t care. (Adverb clause “because she thought he didn’t care” contains the noun clause “he didn’t care.”)

Frequently Asked Questions

Conclusion

Understanding and using subordinate clauses effectively is crucial for constructing complex and nuanced sentences. By mastering the different types of subordinate clauses—noun, adjective, and adverb—and following the usage rules, you can significantly improve your writing and comprehension skills.

Remember to practice identifying and using these clauses in various contexts to solidify your understanding. With consistent effort, you’ll be able to confidently incorporate subordinate clauses into your writing, making it more sophisticated and impactful.