Recall that there are two types of clauses: independent clauses, which can stand on their own as complete sentences, and dependent clauses, which cannot.
EXAMPLEAs you may remember from an earlier lesson, the clause "while he was tired" is a dependent clause because it does not express a complete thought.
There are two ways to make a dependent clause like "while he was tired" into a complete sentence. First, you could turn it into an independent clause and full sentence by completing the thought.
EXAMPLEThe dog was tired.
Here, "the dog" is the subject and "was" is the verb. Or you could use a type of conjunction called a coordinating conjunction to combine it with an independent clause, like this:
EXAMPLEThe dog sat in the doghouse, for he was tired.
Now, two clauses are combined with the conjunction "for." See how the addition of that independent clause ("The dog sat in the doghouse") to "for he was tired" allows a full thought to be expressed? A conjunction is a word or phrase that connects parts of a sentence, and a coordinating conjunction connects two independent clauses into a compound sentence, which is a sentence that contains two or more independent clauses.
Most of the time, a compound sentence will take two clauses that are somehow connected in their content and that are just about equally important to understanding the full thought.
EXAMPLEI want to pet that dog. That dog has fleas.
In the first sentence above, "I" is the subject and "want" is the verb. In the second sentence, "dog" is the subject and "has" is the verb. These sentences offer two good pieces of information, and each tells the reader something important about the situation.
The clauses can be separate, but if joined together, they provide a better understanding of what is going on.
EXAMPLEI want to pet that dog, but he has fleas.
Notice that these two clauses are now connected with a comma and the word "but," which is a coordinating conjunction.
Using the acronym FANBOYS (For, And, Nor, But, Or, Yet, So) is a good way to remember all of these coordinating conjunctions. All of these words are common in English, even for connecting other words and phrases that are not clauses, and each means something really different, changing the implication of a sentence. When you are using a coordinating conjunction to make a compound sentence, you will need to select the correct one.
Take a closer look at each:
- For essentially means "because," which points to a cause-and-effect relationship between the two clauses that it connects.
- And tells us that whatever comes after it is going to add in more information that’s relevant to the first clause.
- Nor is a negating word; it explains that the two clauses are "not," or introduces a clause that will be in the negative.
- But connects two clauses by pointing out that the second clause contradicts the first one in some way.
- Or offers options; it indicates that the reader can choose between the two ideas that the two clauses present.
- Yet works much like "but," but note that it means something very different when you see it outside of a compound sentence.
- So also describes cause-and-effect, but specifically indicates that the second clause will describe something that is the result of whatever the first clause says.
In the following sentences, notice that the coordinating conjunction changes when you want the meaning of the whole sentence to change. In each sentence, there is a clause, then a comma and a coordinating conjunction, and then the next clause:
Sometimes, a coordinating conjunction might be used to connect two words as opposed to connecting two independent clauses; therefore, this would not create a compound sentence.
EXAMPLEThe sentence "I could pet a dog or cat" uses a coordinating conjunction to connect two words.
A sentence that is composed of independent and dependent clauses is going to work a little differently than this. This type of sentence is called a complex sentence, in which one of the clauses is more important than the other.
EXAMPLEI will buy presents for my friends because the holidays are soon.
This sentence starts with an independent clause with "I" as the subject and "will buy" as the verb. Then there is a dependent clause with its own subject and its own verb. The two clauses are connected with the subordinating conjunction "because."
A subordinating conjunction is a word or phrase that connects an independent and dependent clause. You’ve seen coordinating conjunctions, and now you have subordinating conjunctions.
Subordinating conjunctions are used in complex sentences because they indicate that the clause they precede is going to add in the necessary information to complete whatever thought the other clause has started. Some common subordinating conjunctions are "after," "although," "when," "while," and "until."
In some sentences, the subordinating conjunction is the first word, thus meaning the dependent clause comes first.
EXAMPLESince I brought my presents, I am ready for the holidays.
Also note that when the dependent clause is first, it’s always followed by a comma before the independent clause. When the independent clause is first, there will not be a comma between clauses.