Usage of comma before "using" and "which"

English as a Second Language English Vocabulary, Grammar and Idioms
1

Hi all,

I am confused with the usage of commas in these sentences. Take a look at these sentences.

  1. I verified the working of the car using the XYZ simulation tool.
  2. I verified the working of the car when I was at the office, using the XYZ simulation too.

Are the above sentences correct? If so, why are we using comma in the second and not in the first.

One more thing with the usage of commas before “that/which”

The shop responded to the queries that were less than 9 days old.
The shop responded to the queries, which were less than 9 days old.
(indicates all queries were less than 9 old)

I can agree with the importance of comma in the above two sentences. Now, if there was just a single query, then does a comma serve any purpose?

The shop responded to the query that was less than 9 days old.
is same as
The shop responded to the query, which was less than 9 days old.

Which one of the above two sentences is preferred?

Thanks.

2
  1. Using the XYZ simulation tool I verified the working of the car.
  2. Using the XYZ simulation tool I verified the working of the car when I was in the office.

Commas are necessary to separate non-defining (non-restrictive) clauses. However, a comma is not used to separate a clause connected by ‘that’. So, ‘which’ or ‘who’ may be preferred in place of ‘that’.

3

Hi Anglophile,

Thanks. What about the next set of sentences?

4

In my view, whether it is ‘query’ or ‘queries’, it does not need a comma in this context.

5

Hi Anglophile,

I don’t think so.

There is a difference between

The shop responded to the queries that were less than 9 days old.
and
The shop responded to the queries, which were less than 9 days old.

In the first sentence, the shop only responded to the queries that were less than 9 days old, which means there were queries that were more than 9 days old.
In the second sentence, all the queries were less than 9 days old.

6

Yes, if you do not want the two sentences to mean the same and the query to be just single.

7

Absolutely correct. They couldn’t be taken any other way.

8

Again, this is an echo, isn’t it? There is no difference between ‘Yes’ and ‘Absolutely correct’?

9

No, it’s not simply repetition, you said it did not need a comma in this context. Then you said it did IF …
Well, it did. Regardless of the ‘if’.

10

My explanation speaks what I mean.