Take the 2-minute tour ×
English Language & Usage Stack Exchange is a question and answer site for linguists, etymologists, and serious English language enthusiasts. It's 100% free, no registration required.

Please help me with commas in the following sentence:

As an example of the successful use of such a model [,] one can mention SymPy computer algebra system [,] which uses Python as a main user interface.

Is it necessary to write the comma after model? I am not sure whether we can consider "As an example of the successful use of such a model" as an introductory phrase. Also, I am not sure about the second comma.

share|improve this question
add comment

3 Answers

up vote 6 down vote accepted

A comma is required after model because, although the phrase comes at the beginning of the sentence, it is a weak interruption. That is to say, you would still have a viable sentence if you removed it.

You need the second comma, because what follows is a supplementary, not an integrated, relative clause.

share|improve this answer
    
+1, but I think there second could be optional dependant on context. Tell me if you agree with my answer. –  Jon Hanna Feb 3 '13 at 14:48
1  
@Jon Hanna. For the relative clause to be integrated rather than supplementary there would have to be more than one SymPy computer algebra system. –  Barrie England Feb 3 '13 at 15:38
    
Right you are. I asked because something made me lack confidence in my answer, and that's exactly how I should have been thinking. –  Jon Hanna Feb 3 '13 at 16:05
    
Integrated and supplementary, by the way, are the terms used in 'The Cambridge Grammar of the English Language' in place of the more usual defining / non-defining or restrictive / non-restrictive. –  Barrie England Feb 3 '13 at 16:07
    
Funny, I half-suspect that was what led my thinking astray, though were I more used to them in such a context, they probably wouldn't have. –  Jon Hanna Feb 3 '13 at 16:13
add comment

As far as relative pronouns go, a little brown book insists on the comma after "which" because it usually introduces nonessential elements. It opens a relative clause that has more weight than "that."

Companion website to the Little, Brown Book

The exercises on this site are excellent!

share|improve this answer
    
(9th edition, section 28c). –  livresque Feb 3 '13 at 15:43
1  
More than a few allow which in either case though. But +1 because thinking about whether that could serve or would be plain wrong can help tell the cases apart, and would have saved me from the answer I deleted as incorrect. –  Jon Hanna Feb 3 '13 at 16:08
add comment

Both commas are ok, as they are used to indicate where the reader/speaker might pause for a moment, whether reading aloud or silently.

share|improve this answer
2  
But then that just gives us the question "are these places where the reader/speaker might pause for a moment?" While it can be a good intuitive guide to someone fluent in the language to think "would I pause", it doesn't really tell us anything, and it can lead us astray. (I'll admit that it is how I decide this in practice while actually writing, but I do find it sometimes leaves me with some strangely placed commas when I come back to what I've written). –  Jon Hanna Feb 3 '13 at 14:47
add comment

Your Answer

 
discard

By posting your answer, you agree to the privacy policy and terms of service.

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