March 17, 2011

Weekly Language Usage Tips: in conjunction with & using commas correctly

Posted in comma before and, comma in list, commas, in conjunction with at 6:38 am by dlseltzer

Tip 1: In conjunction with

Earlier this week, I was reviewing a grant proposal and found this:

These data will supplement the findings from our ongoing study of patients who take daily doses of aspirin for the prevention of cardiovascular disease. In conjunction, we will use these data to inform the development and evaluation of a new tool for determining the most appropriate age for discontinuing the use of aspirin.

Oh dear. While this study looks at an important issue, it is hard to evaluate the proposal because we need more information. ‘In conjunction’ does not mean ‘in addition,’ and using it on its own like this is a mistake. ‘In conjunction’ can’t stand on its own; something has to be ‘in conjunction WITH’ something. In the example I found in the grant proposal, I assume the author was referring to the data collected in the ongoing study. The problem is that this fact needs to be stated explicitly. There are several ways to reword this. One way would be to combine the two sentences:

We will use the new data, in conjunction with the data from our ongoing study of patients who take daily doses of aspirin for the prevention of cardiovascular disease, to inform the development and evaluation of a new tool for determining the most appropriate age for discontinuing the use of aspirin.

That’s a bit of a mouthful, but at least I know what the writer is saying. ‘In conjunction with’ means the same as ‘in combination with,’ and we have to tell the reader just what is combined with what.

Tip 2: Using commas…correctly

I have been noticing, recently, that some folks are having a really hard time using commas correctly. They use them fine; they use them all over the place, just not correctly. So here is my version of ten ways to use commas correctly and a few places to avoid using commas at all.

Commas are the work horses of the punctuation world. They aren’t glamorous. They don’t stop a thought and end a sentence as the period can. They don’t put together two clauses without a conjunction like a semicolon can. They don’t ask a question like the question mark or express a strong feeling like the exclamation point. What commas do is provide clarity in your writing.

Unfortunately, commas are much abused. They get thrown into sentences willy nilly and any which way. They are included when they aren’t needed and ignored when they are. And worse, once upon a time, someone came up with the idea that commas indicate pauses, and worse still, it stuck. First things first, commas are not pauses!

When to Use and When NOT to Use Commas

1. Use a comma after an introductory word or phrase.

To date, no studies have examined whether prevention screening can accurately be performed online.

[NOTE: When preparing manuscripts or writing grant proposals, be cautious about saying, “To date, no studies have…” The odds are good that at least one study has and that investigator is now reviewing your work. If you are going to state, “To date, no study has…,” be very sure that you are correct.]

In this project, we propose to test the hypothesis that online screening is accurate, cost-effective, and preferred by most people.

In our prior work (Section 5.1.3), we found that uninsured individuals were willing and able to participate.

2. Use a comma to separate independent clauses that are joined by a conjunction (but, and, or, nor, for, so, yet). An independent clause is a clause that has both a subject and a verb and could be a sentence on its own.

We estimate that almost 90 percent of these visits could be treated in a primary care clinic, but we recognize that a small fraction are better suited for the emergency room.

Don’t use a comma to separate independent clauses without a conjunction, use a semicolon instead.

As we highlight below, there is great interest in whether primary care physicians are successfully assuming the role of specialty care physicians; policymakers can use the findings of this study to support or oppose this trend.

Don’t use a comma before a connective phrase joined to an independent clause by a conjunction. Usually, there isn’t a subject in the connective phrase.

[NOTE: This is probably the most frequent misuse of commas that I see. Just because there is an ‘and’ in the sentence, doesn’t mean that there should be a comma.]

We will determine whether primary care clinics differentially affect specialty care utilization for patients with complex medical problems, and if this occurs in areas with different levels of primary care access. LOSE THE COMMA BEFORE THE ‘AND.’

3. Use a comma to separate all items in a list. Use a comma before the final ‘and.’

Most of the research focuses on special populations including the elderly, disabled, pregnant women, individuals from rural populations, minorities, low income, and other populations.

[NOTE: The comma before the ‘and’ is called a serial comma. While leaving out the serial comma is grammatically acceptable, I recommend using the serial comma because it often provides needed clarity (see rule 10, below.]

4.  Use commas to separate parenthetical or explanatory phrases from the rest of the sentence.

Though patients may not be more likely to increase their medications when directed by their physician, in previous work, we have found that they change their medication dose when a family member reinforces the physician’s directive.

[NOTE: I will write about ‘though’ versus ‘although’ next week.]

We will use the RAND-36, a validated scale that measures quality of life, to further examine sex-related differences in outcomes.

5. Use a comma to separate coordinate adjectives, that is, adjectives that modify the noun equally.

The strategy of using generalists to decrease specialist visits represents a larger, more complex delivery system intervention.

In this example, both ‘larger’ and ‘more complex’ modify the intervention equally.

Don’t use a comma to separate non-coordinate (unlike) adjectives.

We will use an innovative economic model to estimate the societal costs.

In this example, innovative not only modifies ‘model,’ but it also modifies ‘economic,’ so it is not a coordinate adjective.

[NOTE: When in doubt, try putting ‘and’ between the adjectives, and try reversing the order of the adjectives. If the sentence still makes sense, then you need a comma; if it doesn’t, don’t use a comma

(e.g., a little, old lady—a little and old lady— an old, little lady—in this example, both ‘little’ and ‘old’ modify lady,’ so these are coordinate adjectives and require a comma;

the red brick building—the red and brick building—the brick red building—in this example, ‘red’ really modifies ‘brick’ and not ‘building,’ so these adjectives are non-coordinate, and a comma would not be used).]

6. Use a comma to separate a quotation from the rest of the sentence.

Dr. Stern said, “These studies highlight the research team’s extensive knowledge of the fields of epidemiology and primary care practice, our prior experience using multiple databases, our analytic strengths, and a track record of publications.”

7. Use commas to set off all geographical names, items in dates (except the month and day), addresses (except the street number and name), and titles in names.

I am meeting with R. Jones, MD, MPH, MSc on March 1, 2011 at 200 Parkvale Building, 200 Meyran Avenue, Pittsburgh, PA.

8. Use a comma to set off a phrase that expresses contrast.

In this section, we provide an overview of our analyses related to Aim 1, not the detail.

9. Use a comma to set off a salutation in a casual letter (in a formal letter, you may want to use a colon).

Dear Johnny,                          Dear Dr. Snyder:

10. Use a comma to avoid confusion. Be careful with this rule, it can lead to overuse of commas. (The first example is widely quoted but is most likely apocryphal.)

I dedicate this book to my parents, Ayn Rand and God.

I dedicate this book to my parents, Ayn Rand, and God.

My professor says Albert has no sense of humor.

My professor, says Albert, has no sense of humor.

And those are the only times to use a comma.



  1. Sue O said,

    I fancy myself as a bit of a grammarian. Is that a word? But every time I read your blog I realize how little I know!

  2. Marcus Ibe said,

    Thanks for your time. I appreciate it.

  3. Anonymous said,

    Great blog. Very informative. Thank you .

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