We learned about adjective or relative clause; we learned that a dependent clause that functions as an adjective in a sentence is called adjective clause or relative. Indeed the adjective clause is divided into two main kinds: defining relative clause and non-defining relative clause. In this lesson we will learn the differences between defining and non-defining relative clauses.
Differences Between Defining and Non-Defining Relative Clauses
1. Defining Relative Clause
Defining relative clause gives essential information about the person or thing that we are talking about in the sentence.
Defining relative clause usually comes after the noun it modifies and the following relative pronouns or relative adverbs are used in defining relative clauses. These relative pronouns or adverbs come at the start of relative clause and refer to a noun or that person in the sentence.
List of Relative Pronouns and Relative Adverbs:
Relative Pronouns: who, whom, which, that and whose.
Relative Adverbs: when, why, and where.
- Students who have not taken admission are waiting outside.
(In this sentence we understand that there are many students in the academy, but we are talking about the ones who have not taken admission, and the class is a defining relative clause.)
- Do you know the man who is standing over there?
- He gave me a parcel which you had sent.
Commas are not used to separate defining relative clauses from the rest of the sentence. Commas or parentheses are used to separate non-defining relative clauses from the rest of the sentence.
No relative pronoun
You can omit the relative pronoun when it is the object of the clause, but when it is the subject of the clause it cannot be omitted. Consider the examples below.
- The teacher (whom) you were talking about is her brother.
- The teacher who taught the lesson was very intelligent.
2. Non-Defining Relative Clause
Non-Defining relative clause gives essential information about the person or thing that we are talking about in the sentence.
The information is not necessary and we don’t need it to understand who or what is being referred to.
The relative pronouns which are used to introduce non-defining relative clause are: who, whom, whose, which and the relative adverb where.
- My brother, who lives in the USA, will come coming Friday.
(In this sentence the information in the non-relative clause is something more about my brother which is not essential information. If the clause is removed from the sentence, the sentence would be still grammatically correct).
- My friend, who won the last match, is now in the final.
- The desk in the corner, which is covered with books, is broken.
Commas or parentheses are always used to separate non-defining relative clause from the rest of the sentence.
Differences with the defining relative clause
1. In defining relative clauses, the pronouns who, whom and which are often replaced by that in spoken English. In non-defining relative clauses you cannot replace other pronouns with that.
2. You cannot omit the relative pronoun in non-defining relative clause, even if it is the object of the verb in the relative clause.
3. Eventually, non-defining relative clauses are always separated from the rest of the sentence by commas, unlike defining relative clauses, which have no punctuation.