Use of Comma before WHICH and BUT.


Could you please explain when putting comma before 'which' and 'but' is not necessary.

I have seen good writers omitting the comma.



Sarvan Minhas

asked Jul 02 '13 at 04:08 Sarvan Minhas New member

4 answers


I agree with Ahmad about using a comma with but.  Here is Grammarly Handbook's explanation:


As for which, there certainly are times that a comma must be used before the word.  When which is used at the beginning of a non-restrictive clause, it must have a comma.  Another comma is placed at the end of that clause.  A non-restrictive clause gives added information that is not necessary.  The meaning of the sentence can be understood without it.  The example given in Grammarly's Handbook ( is:


That box of apples, which I picked this morning, can be used to make the pie.


We don't need to know that the apples were picked this morning to understand that we can use the apples to make the pie.


When which is used to start a restictive clause, then no comma is used. A restictive clause gives information that is necessary for understanding.


The box of apples which is by the door can be used to make the pie.


In this instance, the clause restricts (limits) the subject.  We can't use the box of apples on the table or the one outside.  We can use the one by the door. 

link edited Jul 02 '13 at 10:12 Patty T Grammarly Fellow

Thanks, Ahmad and Patty. I need to work on the nature of clauses.


Sarvan MinhasJul 02 '13 at 14:43

I agree with most of your answer, Patty, but for your restrictive clause, shouldn't you use "that" instead of "which"? The box of apples that is by the door can be used to make the pie.

Actually HollyJul 02 '13 at 16:41

I stand corrected, Holly! Yes, I should have used "that" instead of "which" for a restrictive clause. So I don't actually have an example of "which" being used without a comma before it, then.

Patty TJul 02 '13 at 21:37

It may be interesting to point out that there is also a 'zero relative pronoun' used in informal register and especially in spoken language. [My previous sentence actually uses one!]

For example: This is a problem I just can't understand. More formally, it would read: This is a problem that I just can't understand. I must say, I am personally not tense about defining and non-defining distinctions between who-that and which-that, unless there is direct reference to a person's name, of course [in the case of who-that]. In terms of the use of a comma before 'which' - if you use a non-essential clause [for example an appositive], then a set of commas is actually used before and after the clause, so it's not so much that a comma is used before the relative pronoun.

Ahmad BarnardJul 07 '13 at 11:42

Oh dear - let me just explain before the troll patrol downvotes me: I mean that I am responding, essentially, to the comma-before bit and not to the defining/non-defining bit, except for agreeing with using 'who' where there is reference to a person's name. I am not 'tense' about it MEANS: I am not taking up the cudgel against anything or anyone in this regard. Phew! Hope I have no stalkers, this time! :-)

Ahmad BarnardJul 07 '13 at 11:49

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I think you will find many opinions on this. In my view, 'but' (coordinating conjunction) needs a comma when it joins two independent clauses. However, when. It doesn't join clause + clause, it isn't necessary (unless the sentence becomes too long and clumsy, of course). For example: I live in Al Ain, but I don't live in Dubai. This clause + clause. I live in Al Ain but not in Dubai. This is clause + phrase. As for 'which' - I'm not sure why you expect a comma here. Used as a relative pronoun it doesn't regularly take a comma.

link comment answered Jul 02 '13 at 07:40 Ahmad Barnard Expert

Um, I may be wrong, but I believe those two examples using "which" are grammatically exactly the same. Each is a dependent clause functioning as an adjective to describe the noun "apple." Because they function as adjectives, they are removeable (just as adjectives are). As for the commas, it is my understanding that they do not need it, but I am still looking for a definitive answer. 

link comment answered May 29 '14 at 12:43 Liz Collins New member

From what I've observed, you can know when to use a comma before the word "which" by determining the function of the word and its phrase in a sentence. For example, if the phrase beginning with "which" is describing a noun, then it needs a comma before it, such as in the example sentence "The box of apples, which I picked this morning, can be used to make the pie." The phrase "which I picked this morning" is describing the box of apples, so it's merely describing the subject and unnecessary to the sentence.  However, take this example sentence: "I know which box of apples you are referring to." In this case, the phrase "which box of apples you're referring to" is the direct object of the sentence because it tells us what "I know." Therefore, the phrase is necessary to the sentence and needs a comma before it.  

link comment answered Sep 05 '15 at 15:22 zjmccannon New member

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