Punctuating Nonrestrictive Elements
A nonrestrictive element adds extra information to a sentence but is not needed to identify the noun it describes, so it is always set off with commas.
Reading is good — doing is better. Practice Punctuating Nonrestrictive Elements as an interactive lesson.
Try the lessonDefinition
A nonrestrictive element is a word, phrase, or clause that gives bonus information about a noun in a sentence. If you remove it, the sentence still makes complete sense and the noun is still clearly identified. Because it is not essential, you must place a comma before it and a comma after it (unless it falls at the end of the sentence, where a period replaces the second comma).
Remember the rule
If you can lift it out and the sentence still makes sense with the same meaning, set it off with commas. Nonrestrictive = commas. Restrictive = no commas.
Key words
- Nonrestrictive element
- Extra information in a sentence that is not needed to identify who or what is being talked about.
- Restrictive element
- Information that IS needed to identify the noun—it cannot be removed without changing the meaning.
- Appositive
- A noun or noun phrase placed next to another noun to rename or describe it, like 'my dog, a golden retriever.'
- Relative clause
- A group of words starting with who, which, or that which describes a noun.
- Participial phrase
- A phrase that starts with a verb form (-ing or -ed) and acts like an adjective to describe a noun.
- Essential
- Necessary; cannot be removed without losing important meaning.
- Nonessential
- Not necessary; gives extra detail but the sentence is complete without it.
- Set off
- To separate a word or phrase from the rest of the sentence using commas.
Worked examples
My sister, who lives in Denver, calls me every Sunday.
→ Correct as written. Commas around 'who lives in Denver' are needed. · The writer has only one sister, so 'who lives in Denver' is extra info—remove it and you still know exactly who is meant.
The book that I lost was my favorite.
→ Correct as written. No commas around 'that I lost.' · 'That I lost' is restrictive—it tells WHICH book. Remove it and you no longer know which book is meant.
Mr. Garcia [blank] our science teacher [blank] assigned a project today.
→ Mr. Garcia, our science teacher, assigned a project today. · 'Our science teacher' is a nonrestrictive appositive renaming Mr. Garcia, so it gets commas on both sides.
The dog barking loudly woke the whole neighborhood.
→ The dog, barking loudly, woke the whole neighborhood. (if one specific dog is meant and 'barking loudly' is extra detail) · When a participial phrase is nonrestrictive, it must be set off with commas.
My car [blank] a ten-year-old Honda [blank] needs new tires.
→ My car, a ten-year-old Honda, needs new tires. · 'A ten-year-old Honda' is a nonrestrictive appositive giving bonus info about my car; commas set it off.
Students who study regularly earn better grades.
→ Correct as written. No commas around 'who study regularly.' · 'Who study regularly' is restrictive—it identifies WHICH students. Take it out and the meaning changes completely.
Common mistakes
- Using 'which' without a comma for nonrestrictive clauses—remember, nonrestrictive relative clauses almost always use 'which' and need a comma before them.
- Forgetting the second comma at the end of a nonrestrictive element in the middle of a sentence (writing only one comma instead of two).
- Putting commas around restrictive elements because they seem like extra info—always ask: does removing it change who or what is identified?
- Confusing appositives that need commas with ones that do not: 'my friend Maria' (restrictive—you have many friends) vs. 'my mother, Maria,' (nonrestrictive—you have one mother).
- Skipping commas entirely because the nonrestrictive phrase feels short—even short phrases need commas if they are nonessential.
FAQs
How do I know if something is nonrestrictive or restrictive?
Try the 'lift-out test': remove the phrase or clause. If the sentence still means the same thing and the noun is still clearly identified, the element is nonrestrictive and needs commas. If removing it changes the meaning or leaves the reader wondering which person or thing you mean, it is restrictive and gets no commas.
Is 'which' always nonrestrictive and 'that' always restrictive?
In standard school writing, yes—use 'which' with a comma for nonrestrictive clauses (The trophy, which is gold, sits on my shelf) and use 'that' without a comma for restrictive clauses (The trophy that I won is gold). This rule keeps your writing clear and is what most teachers expect.
What if the nonrestrictive element comes at the very end of the sentence?
You still put a comma before it, but you end the sentence with a period as normal. Example: I called my grandfather, who turned ninety last week. Only one comma is needed because the period closes the sentence.
Does a nonrestrictive appositive always need two commas?
Only when it appears in the middle of the sentence. If it comes at the end, one comma plus a period is correct. Example in the middle: Lena, my best friend, moved away. Example at the end: I miss Lena, my best friend.
Why does this even matter?
Commas around nonrestrictive elements change the meaning of a sentence. 'My brother who plays guitar is talented' implies you have more than one brother and are specifying which one. 'My brother, who plays guitar, is talented' implies you have one brother and are adding a fun fact. One small comma makes a big difference!
Can a nonrestrictive element be more than just a clause—like a phrase?
Yes! Nonrestrictive elements can be appositives (noun phrases), participial phrases (-ing or -ed phrases), or relative clauses. Any extra, removable description of a noun needs commas, no matter what form it takes.
Want the whole picture for your child?
Every K–6 subject, an AI tutor that teaches step by step, unlimited practice, and a reward world.
Start a 3-day free trial