In English grammar, a clause is a group of words that contains a subject and a verb. Some clauses form complete sentences, while others are parts of larger sentence structures. Understanding how clauses work is essential for building clear, well-formed sentences.
This guide explains what a clause is, how it differs from a phrase, and the types you’ll encounter, each with examples to help you recognize and use them correctly.
What Is a Clause in English Grammar?
A clause is a group of words that contains a subject and a verb. It may stand alone as a sentence or form part of a larger sentence.
Clauses help shape sentence meaning and structure. Some express complete thoughts and are called independent clauses. Others rely on additional information to make sense and are known as dependent clauses.
For example:
Lena answered the question is a complete clause with a subject (Lena) and a verb (answered).
Although Lena answered the question is also a clause, but it leaves the thought unfinished. It needs to be connected to another clause to form a full sentence.
Clause vs. Phrase
It’s easy to confuse a clause with a phrase, but they serve different roles in a sentence. A clause includes both a subject and a verb, which means it can often stand on its own or be part of a larger sentence. For example:
She enjoys classical music.
This group of words has a subject (“She”) and a verb (“enjoys”), so it qualifies as a clause.
A phrase, on the other hand, is a group of related words that does not include both a subject and a verb. It cannot form a complete sentence on its own. For instance:
Listening to classical music
This phrase adds meaning, but it doesn’t express a complete thought because there’s no subject doing the action.
The main difference comes down to structure. Clauses are the core of complete ideas in writing, while phrases provide detail but cannot stand alone.
Types of Clauses
Clauses are grouped into two main types based on whether they express a complete thought.
Independent Clauses
An independent clause can stand alone as a complete sentence. It includes a subject and a verb and forms a full idea on its own.
- The students presented their projects.
This clause is complete. It doesn’t need anything else to make sense.
Dependent Clauses
A dependent clause also has a subject and a verb, but it does not express a complete thought. It relies on an independent clause to complete the meaning.
- Because the students presented their projects
This example introduces an idea but leaves the sentence unfinished. It needs another clause to form a complete thought.
Why It Matters
Most English sentences are built using a combination of independent and dependent clauses. Knowing the difference helps you avoid sentence fragments and structure your ideas more clearly.
Functions of Dependent Clauses
Not all dependent clauses serve the same role. Depending on how they function within a sentence, they fall into three main categories: noun clauses, adjective clauses, and adverbial clauses.
Noun Clauses
A noun clause acts like a noun in a sentence. It can serve as the subject, object, or complement.
- What she decided surprised everyone.
In this example, “What she decided” functions as the subject of the sentence.
Noun clauses often begin with words like what, that, who, or whether.
Adjective Clauses
An adjective clause (also called a relative clause) describes a noun or pronoun, giving more detail about it.
- The teacher who guided us retired last week.
Here, who guided us adds more information about the teacher.
These clauses usually start with relative pronouns such as who, whom, whose, which, or that.
Adverbial Clauses
An adverbial clause describes when, where, why, or how something happens. It modifies a verb, adjective, or another adverb.
- We stayed inside because it was raining.
The clause “because it was raining” explains the reason for staying inside.
Common subordinating conjunctions used in adverbial clauses include because, although, if, when, and while.
Combining Clauses
Clauses can be combined to create longer, more detailed sentences. Doing this correctly allows for smoother writing and helps avoid common grammar issues.
Coordinating Clauses
Two independent clauses can be joined using coordinating conjunctions like and, but, or, so, and yet.
- Mia loves painting, and she sells her work online.
Each part could stand alone, but the conjunction and connects the ideas smoothly.
Subordinating Clauses
A dependent clause can be connected to an independent clause using a subordinating conjunction such as because, although, if, or when.
- She sells her work online because she enjoys sharing her art.
The dependent clause “because she enjoys sharing her art” explains the reason behind the main action.
Punctuation Tips
- Use a comma before a coordinating conjunction when joining two independent clauses.
- He applied for the job, but he didn’t get it.
- Don’t use a comma when the dependent clause comes after the independent clause.
- They left early because the weather turned bad.
- Use a comma when a dependent clause comes at the beginning of the sentence.
- Although it was late, they kept working.
Common Errors Involving Clauses
Misusing clauses often leads to unclear or grammatically incorrect sentences. Here are three of the most common mistakes learners make—and how to fix them.
Sentence Fragments
A sentence fragment is an incomplete sentence that lacks an independent clause. It often happens when a dependent clause is left on its own.
❌ After the presentation ended.
✔ After the presentation ended, we asked questions.
Fragments leave the reader waiting for more information, which breaks sentence flow.
Run-on Sentences
A run-on sentence occurs when two independent clauses are joined without proper punctuation or connecting words.
❌ The report was finished it still needed editing.
✔ The report was finished, but it still needed editing.
Run-ons confuse meaning and make writing harder to follow.
Comma Splices
A comma splice happens when two independent clauses are joined only by a comma.
❌ She arrived early, she wanted a front-row seat.
✔ She arrived early because she wanted a front-row seat.
✔ She arrived early. She wanted a front-row seat.
✔ She arrived early, and she wanted a front-row seat.
Comma splices are common in casual writing but should be avoided for clarity and correctness.
Frequently Asked Questions About Clauses
What is a clause in English grammar?
A clause is a group of words that includes a subject and a verb. Some clauses form complete sentences, while others need additional words to make sense.
How is a clause different from a phrase?
A clause has both a subject and a verb. A phrase does not.
Clause: She runs every morning.
Phrase: Every morning
What are the main types of clauses?
Clauses are usually classified into two types:
Independent clauses can stand alone as complete sentences.
Dependent clauses cannot stand alone and must be joined with an independent clause.
Can you give examples of each type?
Yes:
Independent clause: Lena made a sandwich.
Dependent clause: Although Lena made a sandwich
Why should I learn about clauses?
Clauses are the core of every sentence. Knowing how they work helps you write clearly, avoid fragments, and improve sentence variety.
How do I identify a clause in a sentence?
Check if the group of words has both a subject and a verb. If it does, it’s a clause. Then ask—does it express a complete idea? If yes, it’s independent. If not, it’s dependent.
What are common clause-related mistakes?
Here are three to watch out for:
Sentence fragments: Using a dependent clause as if it’s a full sentence.
Run-on sentences: Connecting two independent clauses without punctuation or a conjunction.
Comma splices: Joining two independent clauses with just a comma.