English sentences are composed of clauses and phrases. Understanding how these two units of information work and how to differentiate between them is really important because they’re each essential elements of clear, comprehensible sentences.
A phrase is a small series of words that conveys some meaning, and phrases make up one small part of a sentence. Phrases don’t have to have subjects and verbs, and they don’t need to express a full thought.
Instead, a phrase is just a little chunk of meaning. The most common kind of phrase is a prepositional phrase.
EXAMPLE“In the morning,” and “Without knowing why” are both prepositional phrases.
See how each of those phrases is just one little piece of information, and sets up more information that’s going to come in the rest of the sentence? Prepositional phrases are just one of the many types of phrases you can use.
Often, phrases act like parts of speech and can offer additional information to a complete sentence.
For as long as I can remember, I've wanted a Great Dane, one of the largest dog breeds.
Notice how the phrases add in details that help explain more about the subject and the verb.
Clauses, on the other hand, contain more information. A clause is a group of words that includes a subject and a verb.
There are two kinds of clauses:
Taking a closer look at the differences between them is very important, as you need to be able to put these clauses together correctly to create clear sentences that your readers understand.
An independent clause is a group of words that can stand alone as a sentence, although it does not have to.
You might remember that a sentence is a subject plus a verb plus a full thought; an independent clause is going to contain all of those elements and be able to stand on its own as a sentence, if it wants to.
EXAMPLE“The dog sat in the doghouse” is an independent clause because it contains a subject, a verb, and a complete thought.
This kind of sentence is called a simple sentence. A simple sentence has one independent clause. A sentence with two independent clauses is called a compound sentence. We’ll talk more about those later in this lesson.
A dependent clause is a clause that cannot stand on its own as a sentence. It still has a subject and a verb, but it’s missing that fully expressed thought that lets an independent clause stand alone.
Therefore, a dependent clause is dependent upon connecting to an independent clause in order to become a full sentence.
EXAMPLE“While he was tired” is a dependent clause.
If you wrote this clause as a full sentence, would that be correct?
No, because although the dependent clause has a subject and a verb, it’s missing a complete thought. You need to know what comes before “while” in order to understand this thought.
Often, you’ll see a dependent clause use something called a subordinating conjunction, such as “while,” “after,” “where,” and “until,” among others. Those kinds of words make a clause dependent. We’ll discuss subordinating conjunctions in more detail later.
There are two ways to make a dependent clause such as “while he was tired” into a complete sentence.
You could turn this into an independent clause and full sentence by completing the thought, like this:
The dog was tired.
Or you could use a coordinating conjunction to combine it with an independent clause, like this:
The dog sat in the doghouse, for he was tired.
See how now you have a full thought being expressed? A coordinating conjunction connects two independent clauses into a compound sentence.
As mentioned earlier, a compound sentence 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.
Take a look at the following two separate but related sentences.
I want to pet that dog. That dog has fleas.
These are 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’s going on.
I want to pet that dog, but he has fleas.
Notice that these two clauses are now connected with a comma and then 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 aren’t clauses, and each means something really different, changing the implication of a sentence. When you’re using a coordinating conjunction to make a compound sentence, you’ll need to select the correct one.
Take a closer look at each:
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.
I like to pet dogs, and I also like to pet cats.
I like to pet dogs, but I do not like to pet cats.
I don't like to pet dogs, nor do I like to pet cats.
I don't like to pet dogs, yet I like to pet cats.
In a compound sentence, the comma always comes before the coordinating conjunction. This doesn’t mean that a coordinating conjunction should always be preceded by a comma, though.
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.
EXAMPLE“I could pet a dog or cat,” is an example of a coordinating conjunction connecting two words.
A sentence that is composed of independent and dependent clauses is going to work a little differently than this. These kinds of sentences are called complex sentences, which is where one of the clauses is more important than the other.
Take a look at the sentence below.
I 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. Remember, conjunctions are words or phrases that connect parts of a sentence. You’ve seen coordinating conjunctions, and now you have subordinating conjunctions.
Subordinating conjunctions are used in complex sentences. 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.”
Now consider the following sentence.
Since I brought my presents, I am ready for the holidays.
In this sentence, the subordinating conjunction is the first word, and thus the dependent clause comes first. That’s something you’ll see a lot.
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.
Source: This work is adapted from Sophia author Martina Shabram.