Supposedly, when combining an independent clause with a participial clause, you separate them with a comma. But what about a sentence like:

We built this facility, using the latest technology.

To me, that comma seems odd there.

So if no comma is needed here, what's the difference between a sentence like this, and a sentence like:

He jumped down, creating a cloud of smoke.

  • No need for a comma there.
    – Novelcause
    Apr 2, 2014 at 16:58

3 Answers 3


Use a comma when the participial clause adds extra, unessential information. Don't use a comma when the information is essential (restrictive) to the meaning of the sentence. To put it another way, if it restricts the meaning of any part of the core sentence, as "using the latest technology" restricts the meaning of "built" in your first example (it tells us how it was built), then do not use a comma. On the other hand, if the clause could be omitted without changing the meaning of the sentence, if it adds an extra detail that doesn't really affect the core components, set it off with a comma (such as in the second example, where "creating a cloud of smoke" tells us one of many results of his jumping down).

In some cases, the decision between using and not using a comma depends on what you mean to say. For your first example, with a comma the main point of the sentence is that we built the facility, while without the comma the emphasis is on how we built it.

  • 1
    Yes, it's a pragmatic difference. The possible ambiguity is only marginally possible here - you'd say 'We built this facility, which uses the latest technology.' Apr 2, 2014 at 17:34
  • Ah yes. That reading hadn't even occurred to me. I should probably edit it in somehow.
    – Wlerin
    Apr 2, 2014 at 17:36

The difference between your two examples is that the first one has a restricted clause, and the second is nonrestricted.

"We built this facility using the latest technology." We can't drop the clause because the important information conveyed isn't about who built the facility or what "we" did, but how "we" built the facility. It's a restricted clause (i.e. the participial is necessary to the understanding of the sentence), so the comma can be dropped.

"He jumped down, creating a cloud of smoke." Even without the clause, the sentence still gets the point across, i.e. that he jumped down. "Creating a cloud of smoke" is an unrestricted clause (i.e. the participial is supplementary information), so the comma is necessary.


If you didn't use the comma, "using" would refer not to the subject pronoun "we" but to the word "facility". It would mean that the facility is using the latest technology. In the second sentence, the comma separates the two clauses. "Creating a cloud of smoke" is an optional aside. Oxford Dictionary

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.