A relative clause is a type of ‘dependent clause’ that usually modifies the subject or object of a main clause. This can be a noun or pronoun, but also an adjective or a noun phrase that is functioning as the subject or object of a sentence. A relative clause offers a writer or speaker an alternative to repeating the same words, therefore, making the writing or speech less tedious to its audience or viewers.
A relative clause is introduced by a relative pronoun, such as who, which, that, whose, where or when, and can be ‘defining’ or ‘non-defining’.
Dependent clauses
A dependent clause, often called a ‘subordinate clause’, cannot stand alone as a complete sentence in its own right because it relies on an independent clause, or on being a part of a sentence, to provide a complete thought:
- Although I studied hard, I didn’t pass the exam.
- I didn’t pass the exam, but I tried really hard.
- I really love this book that I’m reading.
Dependent clauses often begin with subordinating conjunctions as with examples 1 and 2, or a relative pronoun as with example 3.
For more on conjunctions please see the relative post.
Defining and non-defining relative clauses
Defining relative clauses are essential to the meaning of the sentence. A defining relative clause cannot be removed without changing the meaning of the sentence, and need not be set off by commas:
- The man who lives next door is a doctor.
A non-defining relative clause (also known as a ‘non-restrictive’ clause or ‘parenthetical’ clause) is a type of relative clause that provides additional information about a noun or pronoun, but is not essential to the meaning of the sentence. Non-defining relative clauses are usually set off by commas, or dashes, brackets or parentheses, and can be removed without rendering the sentence meaningless:
- My neighbour, who is a doctor, always arrives home late.
Relative pronouns
These are the main types of pronouns in English, each serving a specific purpose in replacing nouns and making sentences more concise and coherent by avoiding repetition of the subject or object of the main clause.
Relative pronouns are used to introduce a relative clause, which is a type of subordinate clause that provides additional information about a noun, noun phrase, pronoun or adjective in the main clause of a sentence. Relative pronouns connect the relative clause to the main clause and help to join the two together. As seen in each example below, the subordinate clause (in this case a relative clause because it contains a relative pronoun) can appear as a defining or non-defining relative clause, and either at the end of the sentence, or sandwiched into the middle:
- I love the book, which was written by David Smith.
- David Smith wrote the book, which I love.
- The book, which I love, was written by David Smith.
For more details on subordinate clauses see the relevant post on clauses.
The most common relative pronouns
The following are examples of the most common relative pronouns in English:
Which – used to refer to animals or things:
- The book, which is on the table, is very interesting.
- This book is self-published, which is becoming more commonplace.
That – used to refer to people, animals, or things. It is less formal than ‘who’ or ‘which’:
- The car that I bought last week is blue.
- This is the car that I bought last week.
Before using ‘which’, a comma is traditionally placed whereas a comma is not necessary when using ‘that’. The reason for this is that ‘that’ designates a defining clause and ‘which’ designates a non-defining clause.
In other sentences, the choice as to whether or not to use a comma with the relative clause should be based on whether the relative clause provides the reader with additional information, or whether the relative clause is essential to the subject of the sentence.
For more on comma use, please see the relevant post.
Whose – used to indicate possession and is followed by a noun:
- The man whose car was stolen reported it to the police.
- The police took a statement from the man whose car was stolen.
Where – used to refer to a place or location:
- The park, where we used to play, is full today.
- I visited the park where we used to play as children.
Relative pronouns not only introduce the relative clause but also function as the subject, object or possessive pronoun within that clause. They help to combine two ideas or provide more information about a specific person, thing or place.
When – can also be used as a relative pronoun:
- I remember the day when we first met.
- There are moments when everything seems possible.
Who and whom
Who – used to refer to people in the subjective position of a sentence:
- The woman who lives next door is a doctor.
- There is my neighbour, who is a doctor.
Whom – also used to refer to people, but in the objective position of a sentence:
- The doctor whom I saw yesterday was very kind.
- There is the doctor whom I saw yesterday.
Bear in mind that when ‘whom’ becomes the subject of the next clause (the new ‘doer’ or perpetrator of the next verb) it becomes ‘who’ again:
- There is the doctor I saw yesterday, who gave me some medication.
- Yesterday I saw the doctor, who gave me some medication.
‘Whom’ is increasingly lapsing out of use these days because of the confusion it seems to incur among many English language users, both native and otherwise, and therefore many who use ‘whom’ feel concerned about appearing old-fashioned nowadays. This objective pronoun is no longer viewed as compulsory in informal contexts and many users opt for ‘who’, but it is advisable to continue to use ‘whom’ as appropriate in academic and formal texts.
Structuring relative clauses
Relative pronouns not only introduce the relative clause but also function as the subject, object or possessive pronoun within that clause. They help to combine two ideas or provide more information about a specific person, thing or place.
A sentence can contain two relative clauses as follows:
- The house where I grew up, which is now a museum, is still open to the public.
- The book that I’m reading, which is a mystery novel, is very suspenseful.
Notice that in both the above sentences, the relative pronoun represents the subject of the sentence (the house or the book).
In the sentences below, the relative pronouns represent the direct objects (technology or aid) given in the main clause:
- The English nation has adopted the new technology, which is helping students progress in schools.
- The French government is providing aid to refugees that will help them get by.
Notice that the indirect object in the second example above (refugees) is not what is being referred to by the relative pronoun.
The following is another example of the relative pronoun referring to the indirect object of the main clause:
- The boy kicked the ball to the girl, who was not feeling well.
The reason for this is that a relative pronoun refers to a direct object when it follows the verb, and a relative pronoun refers to an indirect object when it follows a preposition.
Finally, note that in the example below, ‘which’ refers to the adjective ‘self-published’ that is describing the book:
- This book is self-published, which is becoming more commonplace.
So, relative pronouns can also represent other parts of speech, and not pronouns or nouns alone as is commonly asserted, if that part of speech fulfils the role of a subject or object within the main clause. Moreover, relative pronouns can represent a phrase or group of words and not the subject or object alone where they are part of a phrase:
- The Prime Minister talked about the rising living costs, which are a continuing cause of concern among the British people.
In the example above, the complete noun phrase (rising living costs) is the subject of the relative pronoun, including the modifying adjectives and the direct object together. It is the ‘rising living costs’ causing concern, not ‘costs’ alone.
Likewise, with the following example in which the relative pronoun refers to the subject phrase of the main clause:
- The group of passionate computer science students, who are working on the project to develop a new renewable energy source, is making good progress.
In the above example, the relative pronoun ‘who’ refers to the subject noun phrase ‘the group of passionate computer science students.
If you have any further questions or comments regarding the above post, please do enter them below.
Exercises to practise
Have a look at the following quiz on relative pronouns.
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