How to Identify Essential and Non-Essential Clauses

Sometimes a dependent clause is essential to the meaning of the sentence.  Sometimes, dependent clauses add additional non-essential details.  These steps will help you decide if a clause is essential or non-essential.

Step 1:  Read the whole sentence and identify the clause.  Underline the clause

Step 2:  Read the sentence without the clause.  Does it make enough sense?

Step 3:  Read the sentence again, but this time with the clause.  Does it make more sense?

Step 4:  If the sentence makes complete sense without the clause, place commas around the clause.  If the sentence needs the clause to make sense, do not place commas around the clause.


Follow the steps above and practice with these two sentences. Only one sentence needs commas.  Which one?

  • Our hotel which was near the beach offered free room service.
  • The room which has the ocean view is more expensive than the three-room suite.

Answer:  The first sentence contains a non-essential clause, and therefore, will require commas around the clause.

5 Responses to “How to Identify Essential and Non-Essential Clauses”

  1. Hi,
    Thank you again, your tips are great.
    I always try to think about similarities with my language, portuguese, to understand better and assimilate a rule
    About this kind of essencial and non-essential relative clause, in portuguese we have something similar: (i don’t know the technical name in translation, so i will translate it myself):

    essential dependent clause = restrictive adjective subordinate clause

    non-essential dependent clause =
    explanatory adjective subordinate clauses.

    The idea is the same, i think:

    If the sentence make complete sense withouth the clause, put commas around the explanatory clause (non-essential).

    If the sentence make not complete sense without the clause, don’t put commas arount the restrictive clause (essencial).
    That is it, i suppose.
    Great Work.

  2. Hi Vanres,
    It’s always such a pleasure to hear from readers who like this site. Thank you for your kind words. I’m glad the tips were helpful.

    I think your technique of finding a connection between the target language and your primary language is key to understanding. Some people confuse this with translating, but it’s not. Your technique is the right way. Sometimes, the grammars from one language to another won’t correspond as nicely as English and Portuguese, but connecting the fundamentals from one language to another can provide innumerable benefits.

    Are you a teacher or a student? I’m always curious to know who my readers are!

    Thanks again for reading!

  3. Hi,
    Thank you so much.
    These steps are very helpful. I am a teacher. But we have to pass an exam to be a teacher in my country,Turkey. Unfortunately, I couldn’t understand a question related to this topic. Can you help me? The question:

    What kind of structure is the following clause?
    who grumbles whenever the phone rings.
    A) Independent clause
    B) Dependent (subordinate) clause
    C) A complete thought
    D) Essential clause
    E) Nonessential clause

    Thanks again :)

  4. It’s nice to have a visitor from Turkey. I have some friends living there now. Thanks for your kind words. Now, let’s see if I can help…
    Let’s put this phrase into a sentence: The man who grumbles whenever the phone rings is my dad. OR My dad is the kind of guy who grumbles whenever the phone rings. In both examples, the phrase is essential

    It is essential because without the phrase “who grumbles whenever the phone rings”, the sentence would read, “The man is my dad”; this phrase doesn’t provide enough information. It’s dependent/subordinate because it does not express a complete thought.

    I hope this information helps. When is your test? Best of luck!

  5. Thank you very much.
    I agree with you. It is absolutely dependent but the answer key says it is nonessential clause. I think it should have been given a complete sentence in the question like your sentences. Because we can’t decide whether it is nonessential or not. Probably there is something missing in the question. I am so glad to get the answer from a native speaker.
    The test is in July. We have a facebook group in which we have been preparing and helping each other. If you wonder about the exam and want to join us and maybe to help us, you can do.Although there may be Turkish conversations and Turkish questions, most of our members are a teacher of English so you can communicate with them easily.If you want to join us, I can give the link of the group.

    I would be glad to see you in my group.

    Thank you ever so much. :)

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