Discussion Groups / English Usage / January 2007

No. "For this purpose, we have defined X in such a way that it cannot
be misconstrued as Y, which it often is in the field."

That's only one mean of commas around a phrase or clause.

Yes, pauses and disambiguation are two other reasons for commas.

On 27 Jan, 12:43, "418...@cepsz.unizar.es" <418...@cepsz.unizar.es>
wrote:

Use a pair of commas in the middle of a sentence to set off clauses,
phrases, and words that are not essential to the meaning of the
sentence. Use one comma before to indicate the beginning of the pause
and one at the end to indicate the end of the pause.

Here are some clues to help you decide whether the sentence element is
essential:

   * If you leave out the clause, phrase, or word, does the sentence
still make sense?
   * Does the clause, phrase, or word interrupt the flow of words in
the original sentence?
   * If you move the element to a different position in the sentence,
does the sentence still make sense?

If you answer "yes" to one or more of these questions, then the
element in question is nonessential and should be set off with commas.
Here are some example sentences with nonessential elements:

   Clause: That Tuesday, which happens to be my birthday, is the only
day when I am available to meet.
   Phrase: This restaurant has an exciting atmosphere. The food, on
the other hand, is rather bland.
   Word: I appreciate your hard work. In this case, however, you seem
to have over-exerted yourself.

Commas in the wrong places can break a sentence into illogical
segments or confuse readers with unnecessary and unexpected pauses.

"For this purpose, we have defined..., in such a way that...", are
the commas I put correct?

Hi. I would recast this as:
"For this purpose, we have defined...; and in such a way that..."
The fact that you have defined something for some purpose should be
enough material for one clause; in what way you have defined it had
better be the subject of a fresh clause. The latter clause in the
above 'and in such a way that' is in full 'and we have defined it in
such a way that' but the 'we have defined it' bit is suppressed in
ellipsis which is quite legitimate.

That test doesn't work for all sorts of commas.

A pause is not a guaranteed test, either.

You can ride through a town on a bicycle. No comma.
You can ride through a town on such a tiny bicyle that everyone will
stop and stare. No comma.

You can define a term in a particular way. No comma.
You can define a term in such a way that something else follows. No
comma.