What is a main clause?

Learn about the beating heart of all sentences

Taylor Hartley

Taylor Hartley

January 22, 2024

What is a main clause?

Learn about the beating heart of all sentences

Taylor Hartley

Taylor Hartley

Jan 22, 2024

What is a main clause?

Learn about the beating heart of all sentences

Taylor Hartley

Taylor Hartley

Jan 22, 2024

Key takeaways

  • Sentences need a main clause – The main clause is the central idea of a sentence, and every sentence needs one.
  • You need a subject and a verb – For a group of words to be a clause, you need a noun as your subject and a corresponding verb.
  • Not all clauses are created equal – You can have several clauses in a sentence, but only one will count as the main clause.

When you take the first steps into learning the more involved aspects of English grammar, you need to grasp the basic mechanics of the language. That means wrapping your head around a bit of terminology. When you know the names of the different parts of a sentence, for example, you can more easily understand the role of commas, conjunctions and other more minute parts of grammar. 

The main clause is perhaps the most important thing to understand about a sentence. Where the main clause is located, the presence of other clauses around it and how it interacts with other sentence components all determine punctuation and how the sentence is read.

Understanding the structure of main clauses

The main clause is a vital part of any sentence, but what is it exactly?

Essential elements of a main clause

A main clause needs to do a few things. First of all, it needs to be the central idea of a sentence. In other words, the main clause states the information that necessitates the sentence in the first place. Exactly what counts as the central idea can be tricky to determine, so there’s also a more technical definition to know. 

A main clause is a group of words that contains a noun or pronoun that functions as the subject of the sentence. The subject is the person, place, thing, etc. that is doing the main action of the sentence. In addition to a subject, a main clause needs a verb for the subject to do. Together, you get a clause, and if that clause is the main focus of the sentence, it is your main clause.

Identifying a main clause

The main clause can be a little tricky to identify depending on the complexity of the sentence. For simple sentences that have just one clause, that clause is obviously the main one. For other types of sentences that have multiple clauses, you may have two main clauses and a subordinate clause. We’ll go into those situations in a moment, but for now, know that a main clause will be a complete thought that could stand alone as its own sentence. 

Types of main clauses

You’ll work with many different sentence parts when learning grammar, but the two most common types of clauses to know are independent and dependent clauses. However, can those both be main clauses? 

  • Independent clauses. Independent clauses have both a subject and a verb and make up a complete thought. In other words, an independent clause can stand alone as a sentence. For this reason, every independent clause is a main clause. This means that if a sentence has multiple independent clauses, it also has multiple main clauses.  
  • Dependent clauses. While these are technically clauses, they do not count as main clauses. Dependent clauses are also known as subordinate clauses because they have a subordinating word like “because” or “when” which makes the clause an incomplete thought. Since the idea is incomplete, it cannot function as a main clause. 

Relationship between main clauses and sentences

Main clauses and sentences go hand-in-hand, and each type of sentence needs at least one main clause. 

Main clauses in simple sentences

Simple sentences are one independent clause, which makes finding the main clause pretty simple. The single independent clause is the main clause for these sentences. 

For example, “The chicken crossed the road.” This is a simple sentence and the entire thing is the main clause.

Main clauses in compound sentences

With compound sentences, you have two independent clauses connected with a comma and a coordinating conjunction like “and” or “but”. In this case, since you have two clauses that could both stand alone as sentences, you actually have two main clauses in one sentence.

For example, “The chicken wondered what was next, and it quickly decided to cross the road again.” The two independent clauses could each be a sentence on their own, so they are both main clauses. 

Main clauses in complex sentences

Complex sentences have one independent clause and at least one dependent clause. The main clause will always be the independent clause in these sentences, so look for a clause without a subordinator. That’s your independent and main clause.  

For example, “Because he had nothing else to do, the chicken kept crossing the road back and forth.” The first clause starts with “because”, which is a subordinating conjunction That means the first clause cannot be the main clause. That leaves the independent clause in the second half of the sentence as the main clause.

Main clauses vs subordinate clauses

To clarify, main clauses and subordinate clauses can look a lot alike. They both possess a subject and a verb, but the subordinate variety has the addition of a subordinating conjunction. These are words that make an idea incomplete by adding a condition or question to it. 

For example, “The ocean is deep and wide.” This is an independent clause, so it would be a main clause. However, if I add a subordinating conjunction like “since”, the idea becomes incomplete. “Since the ocean is deep and wide…” needs more information to be complete because of the “since”. The reader is left expecting more to the sentence for it to make sense. This is what prevents a subordinate clause from being a main clause.   

In conclusion, main clauses are incredibly important in grammar, but they are also easy to detect and understand. Once you wrap your head around those few tricky situations with subordinators, you will have a solid grasp of the concept.

Explore main clauses with DoodleEnglish

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Designed by teachers, it creates each child a unique work programme tailored to their needs, boosting their confidence and skills in English. Try it for free today!

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FAQs about main clauses

A main clause could be any combination of words that include a subject and verb as long as the idea they create can stand alone as a sentence. An example of a main clause is “The dog chased the cat.”

A subordinate clause is a clause that starts with a subordinating word like since, when, after, because or if. An example would be “Because the weather is nice…”

Yes, a sentence is often just one main clause. 

Yes, they can. When a sentence has two main clauses, it is considered a compound sentence. 

Screenshot 2023-10-13 at 16.29.14

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