Defining and non-defining clauses are both types of relative clauses – clauses that share some extra information about something.
But apart from that the two types of clauses are a little different. Read on to find out what makes each unique!
What is a relative clause?
Before we can identify the differences between defining and non-defining clauses, it’s helpful to understand what a relative clause actually is.
Relative clauses are used to state additional information about the noun in the sentence. It’s usually just a phrase or clause, that’s included as part of the main sentence.
Let’s take a look at an example:
“The celebrity, who was a major film star, was photographed on the red carpet.”
The phrase “who was a major film star” adds some extra information to the sentence, so you can understand a little more about the subject, the celebrity.
Now let’s take a closer look at the two types of clauses.
What is a defining relative clause?
While both types of relative clauses add extra information to the sentence, a defining relative clause clearly adds detail about a specific noun that is defined.
Let’s look at some examples:
“My brother who finished university this summer is spending the year travelling.”
“The house whose doors are shuttered is rumoured to be haunted!”
In both the examples above, you can see an extra clause in the middle of the sentence following the words “who” or “whose” which contain additional information. They relate to a specific noun that has been pointed out uniquely identified: “my brother” or “the house”.
So how do you put together a defining relative clause? You’ll need to use a relative pronoun such as “who”, “whose” or “which”.
An important point to note is that without the additional clause, the sentence would not retain the same meaning.
What is a non-defining relative clause?
Non-defining clauses still add extra information, but not in the same way. While they tell you something additional, they’re not necessary to the meaning of the sentence, but just add an extra non-essential dimension.
“The private yacht, which was rumoured to be the most expensive in the world, belonged to the mysterious couple.”
While the clause certainly tells you something interesting about the topic, the sentence would still retain the main meaning conveyed without it:
“The private yacht belonged to the mysterious couple.”
Non-defining clauses also use relative pronouns, just as defining clauses do. The only difference is that you cannot use “that” with a non-defining clause, unlike defining clauses.
So apart from that, what else makes them different? It’s easy to spot a non-defining clause in writing, as you’ll see that the clause is separated by commas at the start and end of it!
A good way to learn more about defining and non-defining clauses is by reading. So try to read as much as possible and see if you can spot the two types!
Then try and write your own, by creating sentences with some extra information. See if you can separate the difference in meaning between the two types of clauses.