Comma Usage with Dependent Clauses

How to Punctuate Introductory Phrases from the Rest of the Sentence

Oct 6, 2008

Learning when to use commas in introductory phrases will improve your writing, clarify your prose, and help readers get past the sentences and to the main ideas.

Using sentences that begin with introductory phrases or clauses helps add variety and interest to your paper, article, or story, but readers can get lost in your writing if you do not use proper punctuation.

The goal of punctuation, especially commas, is to clarify your writing so readers can better understand your writing. Missing commas in introductory phrases and clauses can lead to misunderstanding, but by learning the rules, you can deliver your message clearly.

Subordinate Clauses

A subordinate clause is a sentence that cannot stand alone. A subordinate clause has a subject and a verb, but it is dependent on something: a full sentence to explain something about the clause.

“Although Josh studied all night” does not read as a full sentence because of the word “although.” By tacking on another sentence relating to Josh studying all night, you can complete the sentence. “Although Josh studied all night, he failed the exam.”

Prepositional Phrases

A prepositional phrase is a phrase that cannot stand alone as a sentence. “Outside of the mall’s main entrance” cannot stand by itself, but you can properly punctuate it into a sentence by adding a comma and a related sentence: “Outside of the mall’s main entrance, rioters held signs and shouted in protest.”

There are numerous prepositional phrases. For a list of prepositional phrases, see this article.

Exceptions

There’s an exception to every rule, especially in English. This means shorter phrases don’t always need a comma before the sentence. Although there is no consensus on the number of words necessary to constitute comma use, many people don’t use a comma if the phrase is under five words. If you can read the sentence aloud without pausing, a comma is not necessary. If you’d like the reader to pause, however, use a comma, even in short phrases.

Transitional Phrases

Transitional phrases always require comma usage, although they are usually short phrases or even single words. “First, you should learn proper comma usage.” or “Above all, remember to be safe.”

There are numerous transitional phrases because transitions indicate relations between sentences and paragraphs. For a list of the types of transitional words and phrases, see this article.

Learning how to punctuate sentences can be difficult, and while the basic rule to place commas where the reader should pause works most of the time, follow the rules before resorting to that trick.

The goal of comma usage is to help readers ease through your writing and comprehend your ideas. The better you understand these rules, the more likely your readers will understand your writing.