Understanding complex sentences is crucial for mastering English grammar. These sentences allow for the expression of more intricate thoughts and relationships between ideas than simple or compound sentences.
By combining independent and dependent clauses, complex sentences add depth and sophistication to writing and speech. This article provides a comprehensive guide to complex sentences, covering their definition, structure, types, usage rules, common mistakes, and advanced topics.
This guide is ideal for English language learners, students, and anyone looking to improve their writing skills.
This article will help you understand how to construct and use complex sentences effectively, enhancing your ability to communicate complex ideas clearly and accurately. Whether you are preparing for an exam, writing a report, or simply aiming to improve your English proficiency, this guide offers valuable insights and practical exercises to help you succeed.
Table of Contents
- Definition of a Complex Sentence
- Structural Breakdown
- Types of Complex Sentences
- Examples of Complex Sentences
- Usage Rules for Complex Sentences
- Common Mistakes
- Practice Exercises
- Advanced Topics
- FAQ
- Conclusion
Definition of a Complex Sentence
A complex sentence is a sentence that contains one independent clause and at least one dependent clause. Independent clauses can stand alone as sentences because they express a complete thought. Dependent clauses, on the other hand, cannot stand alone; they rely on the independent clause to give them meaning. The dependent clause is connected to the independent clause by a subordinating conjunction or a relative pronoun.
Understanding complex sentences is essential for creating more sophisticated and nuanced writing. They allow you to show relationships between ideas, such as cause and effect, contrast, or condition.
By mastering the structure and usage of complex sentences, you can significantly improve the clarity and effectiveness of your communication.
Structural Breakdown
Complex sentences are built from two main components: independent clauses and dependent clauses. The way these clauses are combined determines the sentence’s overall meaning and impact.
Understanding the structure of each component and how they interact is crucial for constructing effective complex sentences.
Independent Clause
An independent clause is a group of words that contains a subject and a verb and expresses a complete thought. It can stand alone as a sentence. In a complex sentence, the independent clause is the main part of the sentence that the dependent clause modifies or adds information to. For example, in the sentence “I will go to the store after I finish my work,” “I will go to the store” is the independent clause.
Independent clauses are essential because they provide the core meaning of the sentence. They can be simple, compound, or complex sentences on their own, but in the context of a complex sentence, they serve as the primary statement.
Dependent Clause
A dependent clause is a group of words that contains a subject and a verb but does not express a complete thought. It cannot stand alone as a sentence and relies on the independent clause for its meaning. Dependent clauses are introduced by subordinating conjunctions or relative pronouns. For example, in the sentence “Because it was raining, I stayed home,” “Because it was raining” is the dependent clause.
Dependent clauses add extra information to the independent clause, providing context, reasons, conditions, or details. They are crucial for creating complex sentences that convey nuanced meanings and relationships between ideas.
Subordinating Conjunctions
Subordinating conjunctions are words that connect a dependent clause to an independent clause. They indicate the relationship between the two clauses, such as cause, effect, time, or condition. Common subordinating conjunctions include because, although, if, when, since, while, until, unless, as, before, and after.
Using the correct subordinating conjunction is vital for conveying the intended meaning of the complex sentence. For example, “I will go to the park if it stops raining” indicates a condition, while “I will go to the park because it is sunny” indicates a reason.
Relative Pronouns
Relative pronouns introduce adjective clauses, which are a type of dependent clause that modifies a noun or pronoun in the independent clause. Common relative pronouns include who, whom, which, that, and whose. These pronouns connect the adjective clause to the noun or pronoun it modifies.
For example, in the sentence “The book that I borrowed from the library is very interesting,” “that I borrowed from the library” is the adjective clause, and “that” is the relative pronoun connecting it to the noun “book.”
Types of Complex Sentences
Complex sentences can be classified into three main types based on the type of dependent clause they contain: adverbial clauses, noun clauses, and adjective clauses. Each type serves a different function in the sentence and provides different kinds of information.
Adverbial Clauses
Adverbial clauses function as adverbs, modifying the verb, adjective, or adverb in the independent clause. They provide information about time, place, manner, reason, purpose, condition, concession, or result.
Adverbial clauses are introduced by subordinating conjunctions.
For example, in the sentence “When the bell rings, we will go home,” the adverbial clause “When the bell rings” modifies the verb “will go” and indicates the time of the action.
Noun Clauses
Noun clauses function as nouns in the sentence. They can serve as the subject, object, complement, or appositive. Noun clauses are often introduced by words like that, what, who, whom, whose, which, where, when, why, and how.
For example, in the sentence “What he said is not true,” the noun clause “What he said” functions as the subject of the verb “is.”
Adjective Clauses
Adjective clauses, also known as relative clauses, function as adjectives, modifying a noun or pronoun in the independent clause. They provide additional information about the noun or pronoun they modify.
Adjective clauses are introduced by relative pronouns or relative adverbs.
For example, in the sentence “The car that I bought is very reliable,” the adjective clause “that I bought” modifies the noun “car” and provides additional information about it.
Examples of Complex Sentences
To further illustrate the structure and usage of complex sentences, let’s look at several examples organized by the type of dependent clause.
Adverbial Clause Examples
Adverbial clauses add detail and context to the main action of the sentence. They can indicate time, place, reason, condition, and more.
The following table provides examples of complex sentences using adverbial clauses.
| Sentence | Dependent Clause (Adverbial) | Subordinating Conjunction |
|---|---|---|
| I will call you when I arrive. | when I arrive | when |
| Because it was raining, I took an umbrella. | Because it was raining | Because |
| She studied hard so that she could pass the exam. | so that she could pass the exam | so that |
| If you need help, let me know. | If you need help | If |
| He went to bed after he finished his work. | after he finished his work | after |
| Although it was difficult, she completed the task. | Although it was difficult | Although |
| I will wait here until you come back. | until you come back | until |
| Since he was not feeling well, he stayed home. | Since he was not feeling well | Since |
| She smiled as she walked away. | as she walked away | as |
| Before you leave, please turn off the lights. | Before you leave | Before |
| He runs faster than I do. | faster than I do | than |
| Wherever you go, I will follow you. | Wherever you go | Wherever |
| She behaved as if nothing had happened. | as if nothing had happened | as if |
| As long as you try your best, I will be happy. | As long as you try your best | As long as |
| He spoke so quietly that I couldn’t hear him. | so quietly that I couldn’t hear him | so…that |
| Unless you hurry, you will miss the bus. | Unless you hurry | Unless |
| She sang while she was cooking. | while she was cooking | while |
| I learned a lot when I traveled abroad. | when I traveled abroad | when |
| He acted as though he were rich. | as though he were rich | as though |
| Now that the rain has stopped, we can go outside. | Now that the rain has stopped | Now that |
| They arrived earlier than we expected. | earlier than we expected | than |
| Because of the traffic, we were late. | Because of the traffic | Because of |
| She exercises so that she stays healthy. | so that she stays healthy | so that |
| Since you asked, I will tell you the truth. | Since you asked | Since |
| I will help you even if it’s difficult. | even if it’s difficult | even if |
| He will succeed provided that he works hard. | provided that he works hard | provided that |
| While I was walking, I saw a friend. | While I was walking | While |
| She looked happy though she was tired. | though she was tired | though |
| Until you try, you’ll never know. | Until you try | Until |
| I’ll bring a jacket in case it gets cold. | in case it gets cold | in case |
This table illustrates how adverbial clauses provide context and modify the main clause, adding depth to the sentence’s meaning.
Noun Clause Examples
Noun clauses act as subjects, objects, or complements within a sentence. They are introduced by words like that, what, who, and how. The following table provides examples of complex sentences using noun clauses.
| Sentence | Dependent Clause (Noun) | Function |
|---|---|---|
| What he said surprised everyone. | What he said | Subject |
| I don’t know what she wants. | what she wants | Object |
| The question is whether he will come. | whether he will come | Complement |
| Whoever wins will receive a prize. | Whoever wins | Subject |
| She told me that she was leaving. | that she was leaving | Object |
| How he did it remains a mystery. | How he did it | Subject |
| I am not sure who is coming to the party. | who is coming to the party | Object |
| What you need is a good rest. | What you need | Subject |
| He didn’t understand why she was upset. | why she was upset | Object |
| The problem is how we can solve it. | how we can solve it | Complement |
| That he is honest is beyond doubt. | That he is honest | Subject |
| I heard that they are getting married. | that they are getting married | Object |
| The truth is that I was wrong. | that I was wrong | Complement |
| What you do is your responsibility. | What you do | Subject |
| She didn’t say where she was going. | where she was going | Object |
| The main thing is that we try our best. | that we try our best | Complement |
| What they decided was kept secret. | What they decided | Subject |
| I wonder if he will call me back. | if he will call me back | Object |
| The point is that we need to act now. | that we need to act now | Complement |
| Whatever you say will be used against you. | Whatever you say | Subject |
| He knows that practice makes perfect. | that practice makes perfect | Object |
| How you feel is important. | How you feel | Subject |
| I realized that I had made a mistake. | that I had made a mistake | Object |
| The issue is that we don’t have enough resources. | that we don’t have enough resources | Complement |
| Why he left is still unclear. | Why he left | Subject |
| They explained how the system works. | how the system works | Object |
| The fact is that we are running out of time. | that we are running out of time | Complement |
| What she believes is her own business. | What she believes | Subject |
| I understand that you are busy. | that you are busy | Object |
This table demonstrates how noun clauses can take on various roles within a sentence, acting as subjects, objects, or complements.
Adjective Clause Examples
Adjective clauses modify nouns or pronouns, providing additional information about them. They are introduced by relative pronouns such as who, whom, which, and that. The following table provides examples of complex sentences using adjective clauses.
| Sentence | Dependent Clause (Adjective) | Relative Pronoun |
|---|---|---|
| The book that I borrowed is very interesting. | that I borrowed | that |
| The man who helped me was very kind. | who helped me | who |
| This is the house where I grew up. | where I grew up | where |
| The woman whose car was stolen is very upset. | whose car was stolen | whose |
| The movie that we watched last night was amazing. | that we watched last night | that |
| He is the student who won the scholarship. | who won the scholarship | who |
| The city where I live is very vibrant. | where I live | where |
| She is the artist whose paintings are famous. | whose paintings are famous | whose |
| The song that she sang was beautiful. | that she sang | that |
| The person who called didn’t leave a message. | who called | who |
| This is the park where we first met. | where we first met | where |
| He is the author whose books I admire. | whose books I admire | whose |
| The cake that I baked is for the party. | that I baked | that |
| The doctor who treated me was very professional. | who treated me | who |
| That is the restaurant where we had dinner. | where we had dinner | where |
| She is the actress whose performance was outstanding. | whose performance was outstanding | whose |
| The gift that he gave me was very thoughtful. | that he gave me | that |
| The teacher who taught us was very knowledgeable. | who taught us | who |
| This is the place where I feel most relaxed. | where I feel most relaxed | where |
| He is the musician whose music inspires me. | whose music inspires me | whose |
| The idea that she proposed was innovative. | that she proposed | that |
| The scientist who made the discovery received an award. | who made the discovery | who |
| This is the country where I want to travel. | where I want to travel | where |
| She is the writer whose stories captivate readers. | whose stories captivate readers | whose |
| The project that we completed was very challenging. | that we completed | that |
| The engineer who designed the bridge is famous. | who designed the bridge | who |
| This is the museum where the artifacts are displayed. | where the artifacts are displayed | where |
| He is the athlete whose achievements are remarkable. | whose achievements are remarkable | whose |
| The solution that they found was effective. | that they found | that |
| The consultant who advised us was very helpful. | who advised us | who |
This table showcases how adjective clauses provide additional information about nouns or pronouns, enriching the sentence’s meaning.
Usage Rules for Complex Sentences
Using complex sentences correctly requires attention to punctuation, subject-verb agreement, and tense consistency. These rules ensure that your sentences are clear, grammatically correct, and easy to understand.
Punctuation Rules
The punctuation of complex sentences depends on whether the dependent clause comes before or after the independent clause. When the dependent clause comes before the independent clause, a comma is used to separate the two clauses. When the independent clause comes before the dependent clause, a comma is generally not needed unless the dependent clause is nonrestrictive (i.e., provides extra information that is not essential to the meaning of the sentence).
Examples:
- Because it was raining, I took an umbrella. (Comma needed)
- I took an umbrella because it was raining. (No comma needed)
- The book that I borrowed from the library is very interesting. (No comma needed – restrictive clause)
- My car, which is very old, still runs well. (Commas needed – nonrestrictive clause)
Subject-Verb Agreement
Subject-verb agreement means that the verb in a clause must agree in number (singular or plural) with its subject. This rule applies to both independent and dependent clauses within a complex sentence.
Examples:
- When he arrives, we will start the meeting. (Singular subject “he” agrees with singular verb “arrives”)
- Because they are late, we will have to wait. (Plural subject “they” agrees with plural verb “are”)
- The book that I read was fascinating. (Singular subject “book” implied in the relative clause agrees with singular verb “read”)
Tense Consistency
Tense consistency means maintaining a logical and consistent use of verb tenses within a sentence. In complex sentences, the tense of the verb in the dependent clause should be consistent with the tense of the verb in the independent clause, reflecting the relationship between the actions or events.
Examples:
- I will call you when I arrive. (Future tense in independent clause, present tense in dependent clause – appropriate for future actions)
- Because it was raining, I stayed home. (Past tense in both clauses – consistent for past events)
- She said that she would go. (Past tense in independent clause, conditional tense in dependent clause – consistent with reported speech)
Common Mistakes
Several common mistakes can occur when constructing complex sentences. Being aware of these errors can help you avoid them and improve the clarity and accuracy of your writing.
| Mistake | Incorrect Example | Correct Example | Explanation |
|---|---|---|---|
| Comma splice | Because it was raining, I stayed home, I watched a movie. | Because it was raining, I stayed home and watched a movie. | A comma splice occurs when two independent clauses are joined only by a comma. Use a conjunction or separate the clauses. |
| Fragment | Because it was raining. | Because it was raining, I took an umbrella. | A fragment is an incomplete sentence. Dependent clauses cannot stand alone. |
| Incorrect subordinating conjunction | Although it was sunny, but I took an umbrella. | Although it was sunny, I took an umbrella. | Do not use “but” after “although” or “though.” |
| Misplaced modifier | I saw a dog running down the street, which was brown. | I saw a brown dog running down the street. | Ensure the adjective clause is placed near the noun it modifies. |
| Lack of subject-verb agreement | What he say are not true. | What he says is not true. | The verb must agree with the subject of the clause. |
| Incorrect tense | I will call you when I will arrive. | I will call you when I arrive. | Use present tense for future actions in the dependent clause after subordinating conjunctions like “when.” |
| Missing relative pronoun | The book I borrowed is interesting. | The book that I borrowed is interesting. | Relative pronouns are often necessary for clarity. |
| Unclear pronoun reference | John told Bill that he was wrong. | John told Bill that Bill was wrong. | Ensure pronoun references are clear to avoid confusion. |
| Redundancy | Because since it was raining, I stayed home. | Because it was raining, I stayed home. | Avoid using redundant subordinating conjunctions. |
| Incorrect word order | That what he said surprised me. | What he said surprised me. | Ensure correct sentence structure when using noun clauses. |
This table highlights common errors in complex sentence construction and provides corrected examples to guide you.
Practice Exercises
Test your understanding of complex sentences with these practice exercises. Identify the independent and dependent clauses, and determine the type of dependent clause (adverbial, noun, or adjective).
| Exercise | Question | Answer |
|---|---|---|
| 1 | Identify the clauses: Because it was cold, I wore a jacket. | Independent: I wore a jacket; Dependent: Because it was cold (Adverbial) |
| 2 | Identify the clauses: The book that I read was fascinating. | Independent: The book was fascinating; Dependent: that I read (Adjective) |
| 3 | Identify the clauses: I don’t know what she wants. | Independent: I don’t know; Dependent: what she wants (Noun) |
| 4 | Identify the clauses: When the bell rings, we will go home. | Independent: We will go home; Dependent: When the bell rings (Adverbial) |
| 5 | Identify the clauses: The man who helped me was very kind. | Independent: The man was very kind; Dependent: who helped me (Adjective) |
| 6 | Identify the clauses: What he said surprised everyone. | Independent: surprised everyone; Dependent: What he said (Noun) |
| 7 | Identify the clauses: If you study hard, you will succeed. | Independent: You will succeed; Dependent: If you study hard (Adverbial) |
| 8 | Identify the clauses: The car that I bought is very reliable. | Independent: The car is very reliable; Dependent: that I bought (Adjective) |
| 9 | Identify the clauses: He told me that he was tired. | Independent: He told me; Dependent: that he was tired (Noun) |
| 10 | Identify the clauses: After I finish my work, I will relax. | Independent: I will relax; Dependent: After I finish my work (Adverbial) |
Exercise 2: Combine the following sentences into complex sentences using the subordinating conjunctions or relative pronouns provided.
| Exercise | Question | Answer |
|---|---|---|
| 1 | Combine: It was raining. I took an umbrella. (because) | Because it was raining, I took an umbrella. |
| 2 | Combine: I finish my work. I will go to the park. (after) | After I finish my work, I will go to the park. |
| 3 | Combine: He is the man. He helped me. (who) | He is the man who helped me. |
| 4 | Combine: She was tired. She continued working. (although) | Although she was tired, she continued working. |
| 5 | Combine: I don’t know. She wants something. (what) | I don’t know what she wants. |
| 6 | Combine: You need help. Let me know. (if) | If you need help, let me know. |
| 7 | Combine: The book is interesting. I borrowed it from the library. (that) | The book that I borrowed from the library is interesting. |
| 8 | Combine: The bell rings. We will go home. (when) | When the bell rings, we will go home. |
| 9 | Combine: He told me something. He was leaving. (that) | He told me that he was leaving. |
| 10 | Combine: You study hard. You will succeed. (if) | If you study hard, you will succeed. |
Exercise 3: Rewrite the following simple sentences as complex sentences.
| Exercise | Question | Answer |
|---|---|---|
| 1 | Simple: I wore a jacket. | Complex: Because it was cold, I wore a jacket. |
| 2 | Simple: I will go to the park. | Complex: After I finish my work, I will go to the park. |
| 3 | Simple: He is the helpful man. | Complex: He is the man who helped me. |
| 4 | Simple: She continued working. | Complex: Although she was tired, she continued working. |
| 5 | Simple: I don’t know her desires. | Complex: I don’t know what she wants. |
| 6 | Simple: Let me know of your needs. | Complex: If you need help
, let me know. |
| 7 | Simple: The book is interesting. | Complex: The book that I borrowed from the library is interesting. |
| 8 | Simple: We will go home. | Complex: When the bell rings, we will go home. |
| 9 | Simple: He told me something. | Complex: He told me that he was leaving. |
| 10 | Simple: You will succeed. | Complex: If you study hard, you will succeed. |
Advanced Topics
For those looking to delve deeper into complex sentences, there are several advanced topics that can further refine your understanding and usage.
Elliptical Clauses
Elliptical clauses are clauses in which some words are omitted because they are understood from the context. These omissions make the sentence more concise and avoid unnecessary repetition.
Examples:
- While walking in the park, I saw a friend. (Omitted: While I was walking)
- If possible, please call me. (Omitted: If it is possible)
- She is taller than I am. (Omitted: than I am tall)
Embedded Clauses
Embedded clauses are clauses that are nested within another clause. This technique allows for the creation of highly complex and layered sentences, enabling you to convey intricate relationships between ideas.
Examples:
- The book that my friend told me about, which I found at the library, is very interesting.
- I think that what he said, which I believe to be true, is important.
- The man who I saw, who was wearing a hat, looked familiar.
FAQ
Here are some frequently asked questions about complex sentences.
What is the difference between a complex sentence and a compound sentence?
A complex sentence has one independent clause and one or more dependent clauses. A compound sentence has two or more independent clauses joined by a coordinating conjunction (e.g., and, but, or) or a semicolon.
Can a complex sentence have more than one dependent clause?
Yes, a complex sentence can have multiple dependent clauses. Each dependent clause adds additional information or context to the independent clause.
Where should I place the comma in a complex sentence?
If the dependent clause comes before the independent clause, use a comma to separate them. If the independent clause comes first, you generally don’t need a comma unless the dependent clause is nonrestrictive.
What are the most common subordinating conjunctions?
Common subordinating conjunctions include because, although, if, when, since, while, until, unless, as, before, and after.
How can I improve my ability to write complex sentences?
Practice identifying independent and dependent clauses, and experiment with different subordinating conjunctions and relative pronouns. Read widely and pay attention to how authors use complex sentences to convey their ideas.
Conclusion
Mastering complex sentences is an essential step in developing advanced English writing skills. By understanding the structure, types, and usage rules of complex sentences, you can express more nuanced and sophisticated ideas.
With practice and attention to common mistakes, you can confidently incorporate complex sentences into your writing, enhancing its clarity, depth, and overall effectiveness. Whether you are writing an academic paper, a professional report, or a creative piece, the ability to construct and use complex sentences will significantly improve your communication skills.