Compound Sentences

In this lesson, we'll cover compound sentences and how to create them by joining two or more independent clauses together. Compound sentences differ from other sentence types, and if you leave out their joining elements, you turn them into run-on sentences. After you review the lesson, you can test your knowledge of compound sentences with a quiz.

Definition

A compound sentence is a sentence that has at least two independent clauses joined by a comma, semicolon or conjunction. An independent clause is a clause that has a subject and verb and forms a complete thought.

An example of a compound sentence is, 'This house is too expensive, and that house is too small.' This sentence is a compound sentence because it has two independent clauses, 'This house is too expensive' and 'that house is too small' separated by a comma and the conjunction 'and.'

Compound Sentences and Meaning

When independent clauses are joined with coordinators (also called coordinating conjunctions) commas and semicolons, they do more than just join the clauses. They add meaning and flow to your writing. First let's look at the coordinators you can use to join independent clauses. They are:

• For
• And
• Nor
• But
• Or
• Yet
• So

Note that they form the handy mnemonic FANBOYS. The three you will use most often are 'and,' 'but' and 'or.'

Here's an example of how coordinating conjunctions add meaning:

'I think you'd enjoy the party, but I don't mind if you stay home.'

In this sentence, the coordinator 'but' shows a clear relationship between the two independent clauses, in this case, that the speaker is making a suggestion that the person being addressed isn't expected to follow it. Without the coordinator 'but,' the relationship isn't apparent, making the writing choppy and the meaning less clear:

'I think you'd enjoy the party. I don't mind if you stay home.'

You can also join independent clauses with a semicolon (;) , which looks something like a cross between a colon and a comma. If you join clauses with a semicolon, you add an abrupt pause, creating a different kind of effect, as shown in the sentence below:

'He said he didn't mind if I stayed home; it soon became clear he wasn't being honest.'

You should use a semicolon when the independent clauses are related, but contrast in a way that you want to stand out. In the sentence above, the contrast is that the person being talked about in the first clause sounded honest when he said he didn't mind if the speaker stayed home, but in the second clause, the speaker is telling you that the person being talked about was not honest. You could just as easily have written the sentence using a coordinating conjunction:

'He said he didn't mind if I stayed home, but it soon became clear he wasn't being honest.'

The sentence still means the same as before, but using the coordinator 'but' softens the impact of the second clause.

Comparing Sentence Types

Sentences give structure to language, and in English, they come in four types: simple, compound, complex and compound-complex. When you use several types together, your writing is more interesting. Combining sentences effectively takes practice, but you'll be happy with the result.

1. The simple sentence is an independent clause with one subject and one verb. For example: 'Katniss can survive in the forest.'
2. The compound sentence is, as noted previously, two or more independent clauses joined with a comma, semicolon or conjunction. For example: 'Katniss can survive in the forest, and she is a capable archer.'
3. The complex sentence combines independent clauses with dependent clauses. For example: 'When equipped with her bow and arrows, Katniss can survive in the forest.'

What Are Compound Sentences (with Examples)

A compound sentence has at least two independent clauses.

An independent clause (unlike a dependent clause) can stand alone as a sentence.

In a compound sentence, the two clauses are joined using:

• a conjunction with a comma (e.g., ", and")
(Read more about when to use commas before conjunctions.)
• a semicolon
(Read more about using semicolons.)
• a colon
(This is rare because the words after a colon are not often an independent clause.)
(Read more about using colons.)
• a dash
(Read more about using dashes instead of semicolons and colons.)
• a conjunction with a semicolon (e.g., "; and")
(This is rare because it's an outdated style.)
(Read more about when to use a comma before conjunctions.)

Examples of Compound Sentences

Below are examples of compound sentences. In each example, the independent clauses are shaded.

• Only two things are infinite, the universe and human stupidity, and I'm not sure about the former. (Albert Einstein, 1879-1955)
• There used to be a real me, but I had it surgically removed. (Peter Sellers, 1925-1980)
• Go, and never darken my towels again. (Groucho Marx, 1890-1977)
(Note: Go is the shortest sentence in English.)
• Any fool can criticize, condemn, and complain - and most fools do. (Dale Carnegie)

The Four Types of Sentence Structure

A compound sentence is one of four main sentence structures, all of which are shown below. In these examples, the independent clauses are shaded.

A Complex Sentence. A complex sentence has an independent clause and at least one dependent clause. For example:

• Diplomacy is the art of saying "nice doggie" until you can find a rock. (Will Rogers, 1879-1935)

A Compound Sentence. A compound sentence has at least two independent clauses. For example:

• Some men are born mediocre, some men achieve mediocrity, and some men have mediocrity thrust upon them. (Joseph Heller, 1923-1999) (Jane Wagner)
(This example has three independent clauses.)

A Simple Sentence. A simple sentence has just one independent clause. For example:

• A country can be judged by the quality of its proverbs. (German Proverb)

A Compound-Complex Sentence.  A compound-complex sentence has at least two independent clauses and at least one dependent clause. For example:

• I stopped believing in Santa Claus when my mother took me to see him in a department store, and he asked for my autograph. (Shirley Temple)