TIL: You need a comma before which and another one at the end of the nonrestrictive phrase; for example:

Jeff’s new car, which is less than a month old, already started leaking oil.

And I learned that we can omit "which is" or "which" in the following sentences.

  • This dog which/that is following us is very big.

    This dog following us is very big.

  • This dog, which has 4 legs, is mine.

    This dog having 4 legs is mine.

My question is: Do we need commas for the last sentence?

Since "having 4 legs" is a nonrestrictive phrase.

This dog, having 4 legs, is mine.

  • IMO, if your intended meaning hinges on the presence or absence of a comma, you're asking to be misunderstood.
    – TimR
    Commented Nov 9, 2018 at 15:58
  • 2
    I'm voting to close this question as off-topic because it's a cross post of the identical question at ELU. One or the other should be removed. Commented Nov 9, 2018 at 17:58

1 Answer 1


No you don't. And if you do insert commas, the implied meaning is different.

To begin with, your example sentence is most unusual.

As nearly all dogs have four legs, it is not easy to distinguish one dog from another by saying that your dog has four legs. So, while the sentence is grammatical, it is puzzling.

Let's change it to read:

The dog having a blue collar is mine.

That's another way of saying: The dog with a blue collar....The dog that has a blue collar....The dog which has a blue collar

And they're all correct options.

If you write:

The dog, having a blue collar, is mine.

Instead of merely identifying your dog by pointing to its collar, you imply that it is because the dog has a blue collar that it belongs to you.

It's a bit like saying:

Because the parcel has my name, it is mine.

It's a change of emphasis.

PS. As it happens I am the owner of a three-legged dog as well as several with four legs.

Your first example would read better if you used the present perfect has (already) started leaking oil rather than just already started leaking oil

  • You're very kind and your answer is very clear. Thank you very much :).
    – hbtpoprock
    Commented Nov 9, 2018 at 16:06

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