Understanding how to use commas to set off nonrestrictive clauses is an important part of mastering written English. These clauses, which add extra but nonessential information to a sentence, should be clearly marked so that readers know the main message is not dependent on them. The proper use of commas in this context helps avoid confusion and ensures that your writing flows smoothly. It also strengthens your grammar, which is essential for academic writing, business communication, and everyday language use.
What Is a Nonrestrictive Clause?
Definition and Purpose
A nonrestrictive clause, also called a nonessential clause, is a group of words that adds information to a sentence but does not change the sentence’s core meaning. This kind of clause is typically introduced by relative pronouns such as who, which, or whose. Because the clause is not essential, it can be removed from the sentence without changing its fundamental meaning.
Examples of Nonrestrictive Clauses
- My brother,who lives in New York, is visiting us next week.
- The book,which I borrowed from the library, was fascinating.
- Sarah,whose painting won an award, is very talented.
In each case, the clause in italics adds helpful detail but is not needed to understand the main subject and verb.
The Role of Commas in Nonrestrictive Clauses
Why Use Commas?
Commas are used to clearly separate nonrestrictive clauses from the rest of the sentence. They signal to the reader that the clause is additional information, not a critical part of the sentence’s meaning. Without commas, readers may interpret the clause as restrictive, changing the meaning unintentionally.
Standard Comma Placement
Nonrestrictive clauses are typically placed in the middle or at the end of a sentence. Here’s how to punctuate them
- Middle of a sentenceThe dog,which barked all night, kept the neighbors awake.
- End of a sentenceWe visited the museum,which had a new exhibit.
Note that when the nonrestrictive clause appears in the middle, it is enclosed by two commas. When it comes at the end, only one comma is needed before the clause.
Nonrestrictive vs. Restrictive Clauses
Key Differences
It’s important not to confuse nonrestrictive clauses with restrictive clauses. A restrictive clause provides information that is essential to the meaning of the sentence and should not be set off with commas.
Comparison Examples
- NonrestrictiveMy sister,who is a teacher, lives in Boston. (The speaker has only one sister.)
- RestrictiveMy sisterwho is a teacherlives in Boston. (The speaker has more than one sister, and the clause specifies which one.)
Adding or removing commas can completely change the intended meaning, so it’s essential to understand the distinction.
Common Mistakes to Avoid
Omitting Necessary Commas
One of the most frequent errors is forgetting to include commas around a nonrestrictive clause. This mistake can confuse readers or give the sentence a restrictive meaning.
IncorrectThe cat who was sleeping on the couch woke up suddenly.
CorrectThe cat, who was sleeping on the couch, woke up suddenly.
Adding Commas to Restrictive Clauses
On the other hand, placing commas around restrictive clauses that should not be set off is also incorrect.
IncorrectThe students, who studied hard, passed the exam. (Implies all students studied hard.)
CorrectThe students who studied hard passed the exam. (Only the hardworking students passed.)
Using Nonrestrictive Clauses in Your Writing
Enhancing Clarity and Style
When used correctly, nonrestrictive clauses can improve your writing by providing helpful background or descriptive information. These clauses allow you to add depth and interest without interrupting the flow of the main idea.
Examples in Context
- My father,who loves gardening, spends hours in the backyard.
- The restaurant,which opened last month, already has excellent reviews.
- Emma,whose laptop broke, borrowed one from the library.
These examples demonstrate how to include additional details while maintaining a clean sentence structure using commas.
Tips for Identifying Nonrestrictive Clauses
Ask Yourself Is It Essential?
When deciding whether to use commas, ask yourself if the clause is essential to the meaning of the sentence. If the sentence still makes sense without the clause, it is nonrestrictive and should be set off with commas.
Check for Relative Pronouns
Look for relative pronouns such as who, which, and whose. While not all such clauses are nonrestrictive, many are, especially when describing a proper noun or a clearly defined subject.
Practice Sentences for Review
Try Punctuating These Sentences
Identify and set off the nonrestrictive clauses using commas
- The Eiffel Tower which is located in Paris is a famous landmark.
- My uncle who is an artist painted that mural.
- Our dog who loves to play fetch chased the ball into the street.
Corrected Versions
- The Eiffel Tower, which is located in Paris, is a famous landmark.
- My uncle, who is an artist, painted that mural.
- Our dog, who loves to play fetch, chased the ball into the street.
These corrections help make the sentences clearer and more readable, while preserving the intended meaning.
Using commas to set off nonrestrictive clauses is essential for clear and effective writing. These clauses add valuable detail without altering the core meaning of a sentence. By learning how to identify nonrestrictive clauses and punctuate them correctly, you can avoid common grammar mistakes and communicate more precisely. Whether you’re writing essays, reports, or everyday messages, proper comma placement helps your readers understand your meaning effortlessly. With consistent practice, you’ll develop a strong sense of when to use commas with nonrestrictive clauses, enhancing both your grammar and your overall writing style.