An introductory clause is a subordinate clause that typically comes at the beginning of a sentence. It provides background information and ‘introduces’ the sentence’s main clause.
How do you write an introductory clause?
Like all other clauses, an introductory clause should include a subject and a verb. (If it doesn’t have both of these, it’s an introductory phrase).
Introductory clauses start with adverbs such as after, although, as, because, if, since, while, though, until, and when. These are also called subordinating conjunctions.
As a general rule, introductory clauses tend to set the scene and tell us something that happened just before or during the events of the main clause. They should be related, at least in some way, to the main clause in the sentence.
An introductory clause should also be followed by a comma, separating it from the main clause.
Here’s a break-down of an introductory clause in a sentence:
The introductory clause is ‘Even though it was raining heavily’ (using the adverb ‘even though’), and the main clause is ‘she still had to walk to school.’ A comma separates the two clauses after the introductory clause.
As you can see, the introductory clause gives the reader some background information about the main clause. First, it explains why she ‘still’ had to walk to school.
It’s also worth noting that you can use introductory clauses at the end of a sentence. While they’re known for ‘introducing’ information, they can add the same information at the end of the sentence and retain the same meaning.
When used at the end of the sentence, the clauses don’t need to be separated by a comma.
Choosing where to place the introductory clause often depends on where you want the emphasis in the sentence to be.
Introductory Clause Examples
Using an introductory clause with dates
We often use introductory clauses when writing dates and times. For example:
Like any other introductory clause, they must be followed with a comma. The clauses can also be swapped and used at the end of the sentence (remember to drop the comma!):
What’s the difference between an introductory clause and an introductory phrase?
An introductory phrase has the same function as a preceding clause but doesn’t include a subject AND a verb. Instead, it contains one or the other.
It relies on the subject or verb in the main clause, but it still provides extra information and helps to set the scene.
There are several types of introductory phrases, such as:
Introductory infinitive phrase
Introductory participial phrase
Introductory appositive phrase
Introductory absolute phrase
Introductory prepositional phrase
Introductory Words
Certain words, called introductory words, help to connect one sentence to the next. They function in a similar way to introductory clauses and phrases.
There is a wide range of introductory words that you can use to transition between sentences in your writing. Here are some examples:
Introductory words to show contrast
Introductory words to add an idea
Introductory words to show the cause
Introductory words to show emphasis
Some of the introductory words you are likely to encounter all the time are: meanwhile, however, still, therefore, furthermore, plus, and moreover. Here are some examples of these super common introductory words in sentences:
How to Use The Different Types of Introductory Phrases
Five main types of phrases fall under the umbrella of the introductory clause definition. Each of these essential phrases serves its purpose within a sentence:
Introductory Prepositional Phrases
The purpose of an introductory prepositional phrase is to add information to the main clause, often concerning location or timing. An introductory prepositional phrase consists of a preposition with a few words following it. Moreover, if the introductory prepositional phrase is longer than four words, it is always directly followed by a comma to set it apart from the rest of the sentence.
Examples of Introductory Prepositional Phrases:
After the scorching hot summer, the grass had all dried up.
Different rules apply when an introductory prepositional phrase comprises less than five words and does not require a pause. In this case, the comma is optional.
On the whole, all of the students were very well-behaved.
On the whole, all of the students were very well-behaved.
Both of these examples are correct, as the comma is optional.
Introductory Infinitive Phrase
An introductory infinitive phrase functions as a way to provide information to the reader, often concerning something that is happening. Introductory infinitive phrases can also provide information about the location and other useful information.
Introductory infinitive phrases are easy to spot, as they always begin with the word ‘to.’ They might also include a direct object of the verb.
Examples of Introductory Infinitive Phrases:
Introductory Participial Phrase
A participial phrase is another form of a verb phrase. The function of a participial phrase is to lay the foundations for the main clause, providing the reader with the context they need to understand what is happening fully.
Furthermore, the construction of an introductory participial phrase is similar to that of an introductory infinitive phrase in a few ways. For instance, it may include a direct object and is always directly followed by a comma.
Examples of Introductory Participial Phrases:
Introductory Absolute Phrase
The purpose of an absolute introductory phrase is to provide additional information to the main clause. But, more than this, an absolute introductory phrase provides context that will inform the reader’s interpretation of the rest of the sentence. To do this, absolute introductory phrases tend to explain how something is done or the reason behind it.
An essential rule about absolute introductory phrases is that they are always directly followed by a comma.
Examples of Introductory Absolute Phrases:
Introductory Appositive Phrase
The function of an introductory appositive phrase is to provide an alternative description of a noun in the sentence. Introductory appositive phrases give the reader more information about the sentence’s subject or another noun.
Often, when using an introductory appositive phrase, a comma is required. However, it is not always a necessity. If the introductory appositive phrase is not necessary for the clarity of the sentence, a comma should always be used directly after it.
Examples of Introductory Appositive Phrases:
Alternatively, if the introductory appositive phrase is necessary to the sentence, a comma is not required after it. However, deciding whether to use a comma after an appositive phrase is essential to determine whether the phrase adds clarifying information about the subject. These clarifying introductory appositive phrases often start with ‘them’ instead of ‘a’ or ‘an’.
Examples of Introductory Appositive Phrases:
When to Use a Comma After Introductory Clauses
The dilemma of when to use a comma after an introductory clause is something that confuses a lot of people. So, to make things crystal clear, let’s dive deeper into when it is necessary to use a comma after an introductory clause and when it is not.
Generally speaking, most introductory clauses are followed by a comma because they are dependent clauses, meaning they cannot stand alone as full sentences. The comma’s function directly after the introductory phrase is to separate the dependent clause from the independent one.
Examples of Introductory Clauses With a Comma:
There are, however, some instances where a comma is not required directly after an introductory clause. For instance, when the introductory clause is short, the comma is optional and can either be included or omitted.
Examples of Introductory Clauses With and Without a Comma:
Both of these examples are correct. Here are some more:
Holding her toothbrush, the boy went upstairs to get ready for bed.
Holding her toothbrush, the boy went upstairs to get ready for bed.
Humming to herself, the student bounced down the stairs.
Humming to herself, the student bounced down the stairs.
Introductory Clauses with Dates
While it is not considered a rule that all introductory clauses containing a date must be followed directly by a comma, it is good practice. It includes all essential clauses concerning dates, whether they have the century, year, month, or day.
Examples of Introductory Clauses with Dates:
On the 12th of March 1967, the popular band, The Velvet Underground released their first album.
Next Thursday, I am going to have my very first driving lesson.
If you switch these sentences around so that the date does not appear as the introductory clause, commas are unnecessary. For example:
