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:
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.
- The simple sentence is an independent clause with one subject and one verb. For example: 'Katniss can survive in the forest.'
- 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.'
- The complex sentence combines independent clauses with dependent clauses. For example: 'When equipped with her bow and arrows, Katniss can survive in the forest.'