You know your best friend. Their name is Sam. You could say, "My friend Sam is funny." But you could also say, "My friend Sam, who has a pet lizard, is funny." The part about the lizard is extra. It's interesting, but you still know who Sam is without it. This is a non-defining relative clause. It is an "Extra Info Friend." It adds a bonus detail about something we already know. Let's learn about these helpful add-on phrases.
What Is an 'Extra Info Friend'?
A non-defining relative clause gives extra information. The information is not needed to understand the main noun. We already know which person or thing we mean. The clause just adds a nice detail. It is like a comment in brackets. You can remove it, and the sentence still makes sense. At home: "My grandma, who lives in Florida, sends me postcards." We know it's my grandma. The clause adds where she lives. At the playground: "The big oak tree, which is over 100 years old, provides shade." We know which tree (the big oak). The clause adds its age. In school: "Mr. Davis, who teaches science, is very tall." We know Mr. Davis. The clause adds what he teaches. In nature: "The sun, which gives us light and heat, is a star." We know the sun. The clause adds a fact. This clause is a friendly add-on.
Why Are These Extra Info Friends So Useful?
Knowing how to use these clauses makes you a skilled storyteller. It helps your ears, your voice, your reading eyes, and your writing hand in special ways.
First, it helps your listening. You hear a fact: "Paris, which is the capital of France, is beautiful." You hear the commas in the speaker's voice. You know "which is the capital of France" is an added fact. You catch the bonus information without getting confused about the main point. It helps you follow interesting details in speeches or documentaries.
Next, it makes your speaking more descriptive and fluent. You can add interesting details smoothly. You say, "My bike, which is blue, is new." This sounds natural and gives a clear picture. You can tell a better story: "My dog Spot, who loves to chase squirrels, barked at a tree." Your listener gets a fuller, more interesting image. Your conversation becomes richer.
Then, it gives you a reading superpower. You read a biography: "Marie Curie, who discovered radium, won a Nobel Prize." You see the commas. You know the middle part is extra information about Marie Curie. This helps you find the main facts quickly. You can separate core information from interesting extras. Your reading comprehension improves.
Finally, it makes your writing more sophisticated and detailed. Your sentences become more advanced. Instead of writing two short sentences: "I have a sister. Her name is Emma. She plays the violin." You can write: "I have a sister, Emma, who plays the violin." This sounds more connected and elegant. Your stories and reports become more engaging and professional.
Meet the Extra Info Starters: WHO, WHICH, and WHOSE
These clauses also start with 'who', 'which', and sometimes 'whose'. But there are important rules! We NEVER use 'that' in non-defining clauses. And we MUST use commas.
First, the People Add-On: WHO. Use 'who' to add extra information about a person. Remember the commas! Look at these examples. At home: "My neighbor, who is a pilot, travels a lot." The clause adds his job. At the playground: "Sarah, who is my teammate, scored a goal." We know Sarah. The clause adds our relationship. In school: "Our principal, who is very kind, smiled at us." We know the principal. The clause adds a description. In nature: "David Attenborough, who makes nature films, has a nice voice." We know who he is. The clause adds what he does.
Now, the Thing & Animal Add-On: WHICH. Use 'which' to add extra information about an animal, thing, or place. Again, use commas! Look at these examples. At home: "My house, which is painted yellow, is easy to find." The clause adds a detail about its look. At the playground: "The fountain, which was built in 1920, is a landmark." We know the fountain. The clause adds its history. In school: "The library, which has thousands of books, is my favorite place." We know the school library. The clause adds a detail about it. In nature: "Elephants, which are very intelligent, have good memories." This adds a fact about all elephants.
Also, the Possession Add-On: WHOSE. We can use 'whose' to add extra information about possession. It means 'belonging to whom/which'. Look at these examples. At home: "My friend Alex, whose father is a chef, eats amazing food." The clause tells us about Alex's father. At the playground: "That artist, whose paintings we saw, is famous." The clause tells us about the artist's work. In school: "My teacher, whose advice I always trust, helped me." The clause tells us about the teacher's advice. In nature: "The old tree, whose branches are huge, is home to owls." The clause describes the tree's branches.
The Golden Rule: Commas and No 'That'
The biggest difference from defining clauses is punctuation. Non-defining clauses have commas. They act like parentheses. You must use commas before and after the clause. Also, you cannot use 'that'. Only use 'who', 'which', or 'whose'. Compare: Defining: "The teacher who teaches math is strict." (Which teacher? The math teacher.) Non-defining: "Mr. Brown, who teaches math, is strict." (We know it's Mr. Brown. The clause adds what he teaches.)
Your Detective Tool: How to Spot Them
Spotting these clauses is easy. Look for the commas! Find a noun, then a comma, then 'who' or 'which', then more info, then another comma. Ask yourself: "If I remove the part between the commas, does the main sentence still make complete sense and identify the subject?" If YES, it's a non-defining clause. Another clue: The noun before the clause is often a name (Paris, Emma), a unique thing (the sun, the president), or has 'my', 'his', 'this' (my grandma, this park).
How to Build Your Extra Info Friend
Building these clauses follows a clear map. The formula is: [Main Noun], + [Who/Which/Whose] + [Extra Information], + [Rest of Sentence]. The 'extra information' is a mini-sentence that could stand alone. For example: "My cat (main noun), who is very lazy (extra info), sleeps all day (rest of sentence)." The commas are part of the formula. They hug the extra information.
Oops! Let's Fix Common Mistakes
Everyone makes mistakes. Let's fix the big ones. The most common mistake is forgetting the commas. A child might write: "My sister who lives in Canada is visiting." This sounds like you have many sisters and you're specifying the one in Canada. If you only have one sister, it should be: "My sister, who lives in Canada, is visiting." Those commas are vital!
Another mistake is using 'that'. Do not say: "My bike, that is blue, is new." This is wrong. Say: "My bike, which is blue, is new." Remember, no 'that' in non-defining clauses.
A third mistake is using a non-defining clause when you need a defining one. If the information is essential to know which one, don't use commas. "Children who are allergic to nuts should be careful." (Defining, essential). "The children in my class, who are all eight years old, are loud." (Non-defining, extra info about a known group).
Are You Ready for an Extra Info Challenge?
Let's test your skills. Think about your favorite celebrity or book character. Write a sentence about them with a non-defining clause using 'who'. Example: "Taylor Swift, who is a famous singer, writes her own songs." Look at a famous building or monument you know. Write a sentence with a non-defining clause using 'which'. Now, think of a family member. Write a sentence about them using 'whose'. Finally, take a simple sentence like "I ate an apple." Add a non-defining clause to make it more interesting. "I ate an apple, which was crisp and red, for a snack."
You Are Now an Extra Info Expert
You have learned all about non-defining relative clauses. You know they add bonus details. You met the starters: who, which, and whose. You learned the golden rule of commas and no 'that'. You can spot them by their commas. You can build them correctly. You can even fix common mistakes. Your English is now more detailed and expressive.
You can learn many things from this article. You now know that a non-defining relative clause adds extra, non-essential information about a noun we already understand. You understand that it is always separated from the main sentence by commas. You learned that we use 'who' for people, 'which' for things and animals, and 'whose' for possession, but we never use 'that'. You saw the key difference from defining clauses: defining clauses identify, non-defining clauses add extra info. You also know the formula: noun, + who/which/whose + extra info, + rest of sentence.
Now, try using your new knowledge in real life. Here are two fun ideas. First, play the "Comma Detective" game. Find a non-fiction book or a news article for kids. Look for sentences with commas and the words 'who' or 'which' inside them. See if you can spot the extra info friends. Second, write a "Fun Fact File" about three people in your family. For each person, write one sentence with a non-defining clause. Example: "My dad, who is a great cook, makes the best pancakes." Share your fact file. Have fun adding those extra details!