What Are Relative Clauses?

Relative clauses are a type of dependent clause. They give more information about a noun or pronoun in the main part of the sentence.

They begin with a relative pronoun (who, whom, whose, which, that) or a relative adverb (where, when, why).

What Is a Defining Relative Clause?

Defining relative clauses provide essential information. This information is necessary to understand exactly who or what you are talking about.

If you remove a defining relative clause, the meaning of the sentence changes or becomes unclear.

• They are not separated by commas.
• You can use who for people, which for things, and that for both people and things.
• Often, that is preferred in informal speech and writing.
• When the relative pronoun is the object of the clause, you can often omit it.

Examples:

• The woman who lives next door is a doctor. (Essential: identifies which woman)
• This is the book which I was telling you about. (Essential: identifies which book)
• I like the car that has red wheels. (Essential: identifies which car)

You can also use where for places, when for times, and whose for possession.

• That’s the restaurant where we had our first date.
• I remember the day when we first met.
• He’s the student whose essay won the prize.

Sometimes, prepositions are used with which ou who. The preposition usually comes at the end of the clause.

• This is the house which I grew up in. (More common than This is the house in which I grew up.)

What Is a Non-Defining Relative Clause?

Non-defining relative clauses provide extra, additional information. This information is not essential to identify the noun.

If you remove a non-defining relative clause, the main meaning of the sentence remains clear and complete.

• They are always separated by commas.
• You use who for people and which for things.
• Crucially, you CANNOT use that dans non-defining relative clauses.
• The relative pronoun CANNOT be omitted, even if it is the object of the clause.

Examples:

• My brother, who lives in London, is a doctor. (Extra: I only have one brother, so “who lives in London” is additional info.)
• The Eiffel Tower, which is in Paris, is a famous landmark. (Extra: “The Eiffel Tower” is already specific.)

Which can also refer to the entire preceding clause, not just a single noun.

• She got the job, which made her very happy. (The job itself didn’t make her happy, the fact that she got it did.)

You can also use where, when, et whose dans non-defining clauses, always with commas.

• My hometown, where I grew up, is very small.
• Last summer, when I visited Spain, was unforgettable.
• My neighbor, whose dog barks all night, apologized yesterday.

Key Differences at a Glance

Here’s a quick summary of the main distinctions between these two important clause types:

Exemples

• The student who submitted the best essay received a scholarship.
• I finally read the book that you recommended.
• This is the café where we first met.
• My car, which is quite old, broke down yesterday.
• Dr. Elena Rodriguez, who is a renowned scientist, will give the keynote speech.
• He failed the exam, which surprised everyone.
• The company whose CEO resigned last month is facing financial difficulties.
• My cousin, whose car was stolen, is very upset.

Entraînement

Erreurs courantes chez les hispanophones

Spanish speakers often make specific mistakes with relative clauses due to differences in grammar structure. Be careful with these common errors:

• Using that in non-defining clauses: In Spanish, “el cual” or “la cual” can sometimes feel similar to that. However, in English, that is never used after a comma.
  • Incorrect: My sister, that lives in Madrid, is visiting next week.
  • Correct: My sister, who lives in Madrid, is visiting next week.
• Omitting the pronoun in non-defining clauses: You can often omit relative pronouns in defining clauses when they are the object. This is never possible in non-defining clauses.
  • Incorrect: The new software, I downloaded yesterday, is very fast.
  • Correct: The new software, which I downloaded yesterday, is very fast.
• Incorrect comma usage: Remember, commas are essential for non-defining clauses but never used for defining clauses. A common error is to add commas to defining clauses.
  • Incorrect: The student, who passed the exam, was very happy. (If there are many students, and this clause identifies *which* student, it’s defining and needs no commas.)
  • Correct: The student who passed the exam was very happy.
• Confusing which et where for places: Use where when referring to a place *as a location*. Use which when referring to the place *as a thing* or when a preposition is involved.
  • Correct: This is the city where I was born. (Focus on the location of birth)
  • Correct: This is the city which I love. (Focus on the city as a thing)
  • Correct: This is the city which I grew up in. (Preposition at the end)

Questions fréquemment posées

What is the main difference between defining and non-defining relative clauses?

The main difference is whether the information is essential or extra. Defining clauses provide essential information to identify the noun and do not use commas. Non-defining clauses provide extra information, are always separated by commas, and the sentence still makes sense without them.

Can I always use ‘that’ instead of ‘who’ or ‘which’?

You can often use that instead of who ou which dans defining relative clauses. However, you can NEVER use that in a non-defining relative clause (the ones with commas).

When can I omit the relative pronoun?

You can omit the relative pronoun (who, which, that) in defining relative clauses when it is the object of the clause. For example, The man (who/that) I saw was tall. You can NEVER omit the relative pronoun in non-defining relative clauses.