August 18, 2011
Weekly Language Usage Tips: commas & em dashes (hyphens and en dashes, too)
I’ve been reading grant proposals, and I discovered that there is a desperate need for reminders of when to use a comma before the word, ‘and,’ and when and how to use em dashes. We’ve talked about both of these issues before, and I had been planning to write about some other topics, but this seemed like an emergency. So here goes.
Tip 1: Using commas before ‘and’
There are two instances in which you use a comma before the word, ‘and,’ and one is even optional.
I’ll start with the optional one first: the serial or Oxford comma. It has other names as well, I’ve heard it called the Harvard comma (no competition between Oxford and Harvard, I see), the series comma, and others. It is used when you have series or list of items ending with an ‘and’ and the final item:
I read four books last week including a book of poetry, a novel, a history of the northwest, and a collection of essays.
As I said, this comma is optional, and you can find factions representing both sides. I recommend using the serial comma because, in some contexts, it will eliminate confusion. For example:
We were offered several choices for dinner including meatloaf, beef stroganoff, vegetable lasagna, and fish and chips.
Is ‘fish and chips’ one of the dinner choices? What if it were written this way:
We were offered several choices for dinner including meatloaf, beef stroganoff, vegetable lasagna, and fish, and chips.
Now, it seems as if ‘fish’ is one choice, and ‘chips’ is another choice.
I found a great example on NPR’s website (npr.org). They pointed out that there was a big difference between:
Meet my wife, my lover, and my best friend.
Meet my wife, my lover and my best friend.
See how the placement of a comma makes a difference! Use it when items are separate, but don’t separate items that should be joined.
Whichever way you go (with the serial comma or without), be consistent within your document: use it (or don’t use it) every time.
The only other time you should use a comma before ‘and’ is when the ‘and’ is separating two independent clauses. [NOTE: A quick reminder, an independent clause is a series of words with a subject and a verb that could stand alone as a discrete sentence.]
I went to the library, and now, I am going to relax and read.
Independent clause 1: I went to the library.
Independent clause 2: Now, I am going to relax and read.
You need a comma because the ‘and’ is separating two independent clauses.
But what about this?
We work regularly with investigators on issues in research design, recruitment, and human subjects protection and represent the University of Pittsburgh in the national meetings.
Independent clause 1: We work regularly with investigators on issues in research design, recruitment, and human subjects protection.
Independent clause 2: THERE IS NONE! ‘represent the University of Pittsburgh in the national meetings’ has no subject and isn’t a sentence on its own and, thus, no comma.
What about this?
Some trainees reported that they would like to hear a talk on the subject of their own research and that they would like a greater proportion of sessions to include video.
Independent clause 1: Some trainees would like to hear a talk on the subject of their own research.
Independent clause 2: THERE IS NONE! Even though there is a noun, ‘they’ and a verbal phrase ‘would like,’ the pesky word ‘that’ at the beginning keeps it from being a complete sentence on its own. So no comma.
Do you see the difference? There has to be an independent clause (complete sentence) on each side of the ‘and’ for you to use a comma. If there isn’t, then no comma.
NOTE: If the independent clauses are short and balanced (I’m on my way to the gym and I’m going to lift weights), then the comma is optional. I would recommend putting it in anyway—just for the practice.]
By the way, this discussion holds true for other little conjunctions (e.g., or, but, yet, so) as well.
Some of our earlier discussions about commas can be found on the pages that start here: https://languagetips.wordpress.com/category/commas/
Tip 2: When and how to use an em dash
An em dash can be used to replace a comma, a semicolon, parentheses, or a colon in writing. It indicates an interruption in thought and can also be used for emphasis. An em dash is called such because it is a long dash, about the length of the letter ‘m.’
An em dash is what we usually see in writing (we use hyphens in compound words and en dashes to indicate a range), but in narratives, the em dash is the key player. This is what you need to know about the em dash: there are no spaces around it! For example,
We will also offer to give specific seminars in our particular areas of expertise—e.g., topics in statistical analysis by Dr. Stata—if requested.
See. No spaces.
In Word, if you print two dashes in a row and you have the ‘AutoCorrect’ feature (and I am being only mildly sarcastic when I say ‘feature’) turned on, the two dashes will become an em dash. Or if you are like me and don’t use ‘AutoCorrect,’ you can create an em dash by going to the insert menu and choosing ‘symbol’ and then ‘special characters’ and then ‘em dash.’ Another easy way to do this is to press CTRL ALT and the hyphen character on the key pad on the PC or CMD OPT and the hyphen character on the key pad on the Mac.
So my take home messages about the em dash are these:
Don’t use an en dash for an em dash (reserve the en dash for ranges (e.g., anyone from 14–64 is welcome).
Use em dashes sparingly (it is disconcerting to see tons of them peppered throughout your prose).
Don’t have any spaces around em or en dashes (although sometimes the en dash is represented by a hyphen with a space on either side).
And that’s it.
Our previous discussions on hyphens, en dashes, and em dashes start here: https://languagetips.wordpress.com/category/hyphen/.
I hope this helps quell the emergency!