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Comma before “which” in the UK (British English) — Rules

Comma before “which” in the UK (British English) — Rules

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Human curiosity has come to a point where people ask specific questions like “When do we need to place a comma before ‘which’ in the UK?”

What this question actually means is whether there is any significant difference between how British and American English users use their commas.

Whether to use a comma or not before the word ‘which’ is one of the most popular, or more like notorious, questions people ask despite knowing the basics of writing.

So, our post today focuses on addressing these very issues, which are pretty much rooted in how the English language grammar works in general.

Let’s start with a simple answer.


When does a comma come before “which” in the UK (British English)?

A comma comes before “which” when it introduces information that is not grammatically necessary to the sentence. In the UK or more particularly in British English, a comma comes before “which” when it introduces a piece of information whose meaning is just intentionally added for emphasis.


Getting to know the word “which”

The word “which” can be used as a pronoun, a determiner, and even a conjunction sometimes in the English language.

“Which” is a pronoun when it completely replaces a noun in a sentence. This usage is better seen when “which” is used as a question word in an interrogative sentence.

In this case, we also call “which” an interrogative pronoun:



Which are the best countries to visit in summer?


More particularly, “which” can also be used as a relative pronoun to refer back to a previously mentioned noun phrase in the same sentence.



This brown leather wallet, which is very old, used to be my dad’s.


Meanwhile, “which” acts as a determiner when it is used to identify and refer to certain nouns that may have more than one alternative.

This usage is better seen when “which” comes before a noun in a sentence.



I wanted to know which restaurant in Boston is the best.


Thirdly, dictionaries also list “which” as a conjunction. This is the case when “which” is used to connect a dependent or subordinate clause to the main clause.

This is particularly true in the informal use of English because the informal or casual register allows a freer or more convenient language use.

In the sentence below, “which” is conveniently used as a conjunction. However, when the word “one” is used after it, it turns into a determiner instead.



How do you recognize which (one) is your dog?


Now that we have covered the basics, placing a comma before “which,” no matter whether in the UK or USA, should already be less tricky.


The appropriate comma usage before “which” in the UK

For starters, the punctuation rules between the UK and the USA are generally the same. This means that there are actually more similarities than differences between the two.

In reality, the “rules” that govern whether to place a comma before “which” are the same in most, if not all, English variants to date.

This is because punctuation largely depends either on the structure of the language or the writer’s intent rather than the language variant itself.

When it comes to the English language variations, what would likely differ are those that are related to meaning, pronunciation, accent, and even formality level.

For example, American English more specifically distinguishes the use of “which” vs. “that” in sentence construction, while British English doesn’t.

From this angle, we can understand that the word “which” is used in British English in a more general and less complicated manner.

If that’s the case, then how exactly does the comma work in British English in connection with the word “which”?

The next three sections elaborate more on this concern.


When “which” introduces a non-restrictive relative clause

A relative clause is a piece of grammatically stand-alone information that acts as an adjective or identifier to a noun contained in the same sentence.

A comma before a relative clause is used when it introduces something that is only “additionally” added to make the sentence more meaningful.

On the other hand, the comma is intentionally left out if the relative clause is grammatically necessary to the meaning of the whole sentence.

A “non-restrictive” relative clause is just what we specifically call relative clauses that are grammatically unimportant.

By being grammatically unimportant, this kind of clause is only used to “improve” or “boost”  the meaning of a sentence.

Because a non-restrictive relative clause is used this way, it does not limit the meaning of a sentence, hence the dispensability.

Here’s an example of “which” being used as a relative pronoun used to introduce a non-restrictive clause.

In the next example, the meaning of “which” can only be understood by referring back to the subject used in the sentence.



The which-clause in this sentence, which is not really important, can be taken out.

As you can see, “which is not really important” is used to describe and refer back to “the which-clause in this sentence.”

A comma is placed before “which” in the example above because it only introduces an additional piece of information or a side comment.

As suggested, the which-clause in the example can actually be removed from the sentence. Even when removed, the remaining parts can still make sense.

Note, though, that the main verb has only been intentionally changed to make the meaning of the sentence more fitting and time-bound.



The which-clause in this sentence has been taken out.


When “which” introduces an afterthought or parenthetical expression

Another case that prompts the pre-comma usage is when “which” introduces a parenthetical expression or an afterthought.

This rule is actually just the same as the first one earlier but taken from the view of rhetorical or creative language use instead of syntax or sentence construction.

A parenthetical expression is just a piece of information added to make an utterance or sentence more interesting. They are also known as free modifiers.

Afterthoughts could be more observable when we use spoken language because we get to hear the tone of voice as well as see the facial reactions and body gestures of the speaker.

Since we don’t really get to notice these things in the written language form, we make use of commas to imitate them textually.

So, if this is how we want to make use of the word “which,” which we can also just call a “non-restrictive relative clause,” a comma before it is necessary.



Stinky tofu, which apparently stinks, is good for the health.


Without the parenthetical information “which apparently stinks,” which is a side comment or afterthought, the sentence still makes complete sense.



Stinky tofu is good for the health.


When “which” is used after a parenthetical expression

Now that we know that “which” can be used to introduce a non-restrictive relative clause, which we can also identify as a parenthetical expression, understanding this last rule should be a lot easier.

A comma before “which” is also necessary when “which” comes after a parenthetical expression.

The final comma of the parenthetical expression also serves as the comma before “which,” as in the next example:



That design, not to say it’s bad, which is harsh, can still be improved.


In the example above, the comma before “which” is definitely necessary because it is preceded by a parenthetical comment, which also needs to be ended with a comma.

Apart from that, we can also understand that “which is harsh” is also just another parenthetical comment placed after another parenthetical comment, hence the comma.


The incorrect comma usage before “which” in the UK

If there are right ways to use a comma before “which,” there must be incorrect ones too. In this section, you will find two cases in which you should avoid your comma.

Once again, it is worth noting that the comma decision that we have to make heavily depends on how we want to structure our sentence as well as how we want to convey creativity.


When “which” introduces a restrictive relative clause

In British English, the use of “which” and “that” are not necessarily as distinct as in American English.

This simply means that British English users would rather use “which” instead of “that” even for restrictive or grammatically important clauses.

This might be an easy case when it comes to simply knowing how to use “which” in a sentence; however, the comma decision is a different ball game.

This suggests that we have to use our intuition when deciding when to use a comma before “which” when writing according to British English conventions.

Contrary to non-restrictive relative clauses, restrictive clauses are those that bear grammatically significant meaning based on the host sentence.

Restrictive clauses are those we need to complete the meaning of a sentence. Thus, removing them makes the remaining parts ambiguous.

Take a look at this example:



The book which I left here earlier is gone.


In the example above, “which I left here” is necessary to complete the meaning of the sentence, or else the hearer or reader won’t understand it at all.

Yes, it is grammatically possible to say “The book is gone,” but we wouldn’t understand which exact book is being referred to by the subject.

In other words, “which” in the last example sentence is used like “that.” If the sentence were written according to American English standards, it would read more like this:



The book that I left here earlier is gone.


When “which” comes with a preposition

“In which,” “to which,” “on which,” and “of which” are probably the most popular phrases that should tell us to drop our commas.

In these phrases, “in,” “to,” “on,” and “of” are prepositions, while “which” is the object being referred to by the prepositions.

When using these phrases in more complete sentences, other words are expected to come after “which” – the modifiers.

When we combine prepositions with “which” as well as any succeeding modifiers, we get what we call “prepositional phrases.”

Like the usual prepositional phrases, we do not split the preposition from the object or noun phrase it refers to, especially in formal English.

Using a comma before “which” in this case will make the construction ungrammatical. So, do not place a comma before “which” when you create sentences like this:



She wrote a screenplay in which Jonie is the main character.

The sentence above is actually just a combination of two sentences. We do this sentence combination to make our sentences richer and shorter.



She wrote a screenplay. In this screenplay, Jonie is the main character.


British English vs. American English with regards to the usage of “which”

As you may figure, there are both pros and cons as to how British and American English users make use of the English language.

If you decide to follow the British standards, you would most likely find it easier to speak English because you need not distinguish between “which” and “that.”

On the other hand, you also would more likely get confused when to punctuate “which” with a pre-comma when writing.

The situation is the other way around in American English. While you get to use easier writing strategies, you would meanwhile have a harder time deciding when to use “which” and “that” when speaking.


Frequently Asked Questions on “Comma Before ‘Which’ in the UK”


What does putting a comma before “which” mean?

Putting a comma before “which” generally means that we are introducing a piece of additional information to make our sentence more interesting. In other words, it means we do it to add emphasis.


Do I need a comma before “which includes”?

Generally, we need a comma before “which includes” because we use this phrase to add extra information. This extra information is usually a series of examples. Instead of commas, we may also use parenthetical marks to set the extra information apart from the rest of the main sentence.


What is an example of a sentence with a comma before “which”?

The following sentence makes use of a non-restrictive relative clause that needs to make use of a comma before “which” as well as at the end of the clause: This new pair of shoes, which I really love, was my mother’s gift.”