Relative clauses can be essential (defining) or nonessential (non-defining) to the meaning of a sentence.
Essential relative clauses (defining relative clauses) provide information that is necessary to the meaning of the sentence.
Nonessential relative clauses (Non-defining relative clauses) provide additional information that is not necessary to the meaning of the sentence.
Here are some examples to illustrate the difference between essential and nonessential relative clauses:
| Type of Clause | Example | Explanation |
|---|---|---|
| Essential Relative Clause | The book that I borrowed from the library was very interesting. | This relative clause is essential because it provides crucial information about which book is being referred to. |
| Nonessential Relative Clause | John’s car, which is a red convertible, is parked outside. | This relative clause is nonessential because it provides additional information about John’s car, but it is not necessary to understand which car is being referred to. |
| Essential Relative Clause | The woman who won the award gave a speech. | This relative clause is essential because it specifies which woman is being referred to. Without this information, the sentence would be incomplete and the meaning would be unclear. |
| Nonessential Relative Clause | My neighbour, who is a doctor, is very kind. | This relative clause is nonessential because it provides additional information about the neighbour, but it is not necessary to understand who the neighbour is. The sentence would still make sense without this clause. |
When we use relative clauses in English, sometimes we need to separate them from the rest of the sentence with commas, and other times we don’t. This all depends on whether the information in the clause is necessary or not. If it’s necessary, we don’t use commas; if it’s just extra information, we do use commas.
Understanding the difference between essential and nonessential relative clauses is important for clear and effective communication in writing and speaking.
Grammar Practice
Speaking Practice
Combine each pair of sentences into one sentence using a non-defining relative clause.
Writing Practice
Write some of your own sentences about where you grew up, things you’ve done recently and people you know. Use non-defining relative clauses to add extra information.
I grew up in … I recently … I have a friend called …