Restrictive & Non-Restrictive Adjective Clauses

Can adjective clauses, which can be confusing for students, ever be easily learned?

As if adjective clauses (also called relative clauses) weren’t complicated enough already, our students also need to learn when to add punctuation. In my experience, some textbooks deal with the punctuation issue much later on or not at all in an adjective clause lesson. I prefer to explain it to my students fairly early on before they start practicing doing the wrong thing. The following are some teaching tips on the punctuation of restrictive and non-restrictive adjective clauses. (And does anyone else get the terms restrictive and non-restrictive mixed up? I always had to double-check before class!) Check back on our blog for more posts about adjective clauses and phrases, such as which pronoun to use, formality, when the pronoun can be dropped, etc. Coming soon!

Restrictive Adjective Clauses

Restrictive adjective clauses (also known as defining adjective clauses) contain information that is necessary to define the noun. The noun is a general noun such as boy, apple, book, city, etc. A good tip to tell your students is that if the meaning is any, then it’s a general noun (book = any book; I don’t have a specific book in mind).

Because the noun is general, it needs information to specify/define it so that we know which noun the speaker is talking about. The adjective clause, then, is important information that defines the noun, and because it is important, no commas are needed. (Remind students that commas are often used to offset secondary, less important information in English.)

Point out that even though the noun is general, the adjective clause is going to define the noun, so we need the article the, never a, with adjective clauses that are defining a subject noun. For an object noun, either article is possible.


  • The boy who is running around the room is my son.
  • I met the boy who was running around the room.
  • The woman who is wearing the red dress told me the time.
  • The apple that I had at lunch was delicious.
  • The book that I finished reading yesterday was really interesting.
  • I finished reading a book that was really interesting.
  • The city that I want to visit the most is Paris.

Non-Restrictive Adjective Clauses

Non-Restrictive adjective clauses (also known as non-defining adjective clauses) contain information that is NOT necessary to define the noun (it is simply extra info). The noun is a specific noun such as the proper name of a person, place, or thing, or a noun already defined by a pronoun/adjective/attributive noun, etc. A good tip to tell your students is that if it’s clear which noun the speaker is talking about, then it’s a specific noun (Paris = a specific city; I know which city it is).

Because the noun is specific, it DOESN’T need information to specify/define it because we already know which noun the speaker is talking about. The adjective clause, then, is extra information that doesn’t define the noun, so commas are needed. (Remind students that commas are often used to offset secondary, less important information in English.)


  • My son, who is running around the room, had too much sugar earlier.
  • I scolded my son, who was misbehaving in front of my guests.
  • Mr. Jones, who is my teacher, has been at this school for 25 years.
  • My lunch, which I ate in five minutes, was delicious.
  • The Hobbit, which was an excellent book, was made into a movie.
  • I finished reading the Hobbit, which was made into a movie.
  • Paris, which I visited last year, has a lot of interesting architecture.

Note: Be aware that some textbooks don’t use the hyphen (they use nonrestrictive)—stick with the word/spelling used in your students’ main textbook.


Try ESL Library’s related lessons:

Final Note:

I plan on writing another blog post or two about which pronouns to use with restrictive/non-restrictive adjective clauses, but I’ll mention one case here because it involves punctuation. Many people follow this rule:

Use that for restrictive adjective clauses and which for non-restrictive adjective clauses.

(I.e., use that when there’s no comma and which following a comma.)

Examples: The book that I finished reading was great. / My science textbook, which was boring, took me a long time to read.

Note that these rules are very common in American and Canadian English. In the UK, which is still accepted in both types of clauses, according to the New Oxford Style Manual. What about other English-speaking countries? My colleague from New Zealand said that they use that in restrictive clauses, not which. I’d love to hear from other people in the comments section below!


Leave a Comment ↓


    Rodolfo says:

    Mar 24, 2017 at 11:17 pm

    Hello, Tanya
    I’m sorry I’m late to the party, but I have a few question regarding the way you describe the use of WHICH. I mean, from what I’ve heard, I was told that THAT is the relative pronoun that restricts, which is why it never comes followed by a comma, whereas WHICH only adds non-restrictive information to the sentence, which is why it’s considered non-restrictive.
    Could you please confirm such information or suggest a fix? Thanks.


    • Tanya Trusler says:

      Mar 27, 2017 at 2:56 pm

      Hi Rodolfo,

      You are correct! We use “that” for important (restrictive) information, and we don’t use commas. We use “which” for less important, extra information (unrestrictive), and we use commas.

      Just be careful to follow the rules based on where you’re teaching or studying. This is how we do it in North America, but in British English, I believe “which” is commonly used for both cases (with no commas for restrictive clauses, and commas for unrestrictive clauses, as usual).



    blair says:

    Feb 23, 2016 at 7:48 pm

    what’s the different between which and that?


    • Tanya Trusler says:

      Feb 24, 2016 at 12:39 pm

      Hi Blair,

      In restrictive clauses, “which” and “that” are both pronouns that replace a “thing” (i.e., they have the same meaning). The difference is that in American and Canadian English, “that” is used in restrictive clauses (without commas) and “which” is used in restrictive clauses (with commas). In British English, “which” is used in both types of clauses. In fact, even in North America, “which” can be used in restrictive clauses, but note that it sounds a lot more formal to use it that way and some people will argue that it’s incorrect.


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