Why does it seem that nobody knows the correct way to end a comma-delimited list? Did they stop teaching this after 1990 or something? Let’s review, shall we?

First let me explain the philosophy upon which the correct use of “commas in lists” rests. It’s another topic that I realize they almost definitely stopped teaching after 1980: mathematics. Take the following expression:

1 + 1 × 3
Grammar must have algorithms or else it’s useless.

If you studied mathematics in school you should remember the algorithm that is used to resolve it. There are no special characters in this expression, so we evaluate any division or multiplication first, then addition and subtraction, and we go from left to right. So this expression — in your mind — looks like this:

1 + whatever I get when I multiply 1 and 3

The expression evaluates to 4, of course. To make the expression easier, you could add brackets or parentheses:

1 + (1 × 3)

That equals 4 as well, and is, in fact, logically equivalent to the first expression.

Let’s mix it up a bit! Change the arrangement of the parentheses to this:

(1 + 1) × 3

This is completely different! See? Our rules tell us to evaluate values inside parentheses or brackets first! So this expression — in your mind — looks like this:

first get the sum of 1 and 1, multiply that sum by 3

Do you see why this matters? This expression contains the exact same values and the exact same logical operators (the plus sign and the multiplication sign) but it does not evaluate the same way! This expression evaluates to six. In the algorithm used to solve equations like this, the parentheses have precedence over any other logical operators.

Now this is where it gets exciting! The rules of grammar — I know for a fact that they stopped teaching these in 1990 — follow similar algorithms! I know, I know. “That’s crazy talk,” you say. But it’s true. Grammar must have algorithms or else it’s useless. A language that has no rules, well that’s no language at all. People are always griping and complaining to me about how flexible the English language is. People say that there are no “rules” in English. That’s not true. There are rules. It’s just that we — humans — are smart enough to understand each other in spite of the fact that we break the rules.

Some of you might be thinking, “Hey! This is sort of like the web standards thing that Zeldman is always trying to tell us!” That’s correct. The hypertext markup language (HTML) upon which the web is based has rules. It has rules in the same way that the English language has rules. When your browser looks at a web page, it reads the HTML — which is pretty ugly and hard to read — and converts it into something to display to you. This is analogous to your ears and brain converting the words coming out of my mouth — which sound pretty strange if you really think about it — into a comprehensible thought. It’s analogous to your eyes and brain converting little squiggles on a piece of paper into a comprehensible thought. Get it?

Our brains are really smart. I’m not kidding. Take the coolest, fastest, grooviest supercomputer on the planet. Even if it can beat me at chess, I’m still smarter. So are you. Brains just work better than computer chips. They might not always be smarter than computers, but as of right now there aren’t any computers that can be considered smarter than a brain. A web browser reads HTML and it tries to be forgiving. What does that mean? It means that if the person that wrote the HTML forgot to close a tag, the browser will try to compensate for you and not destroy the web page before it displays it. This is similar to me not putting my fist through someone’s face when they say, “impacting.” Impacting should not be something that is allowed. An “impact” is a thing.

BOOM! Look! A meteor just landed on that Cadillac! Did you see the impact?

At what point was anything “impacting”? You maybe could argue that for a millisecond the meteor was “impacting” the Cadillac. (I’d argue that you are an ass. But that’s not the point.) An impact is a thing; it’s not a happening.

But we are a forgiving people and we have forgiving brains. So when you talk to me you say, “Wow! Did you see that new movie with Ah-nuld? It’s really impacting our society!” I am forgiving. I don’t freak and punch you in the face and exclaim, “You sound like a complete moron, you jerk.” No. My brain takes the senseless noises you are making and converts them into something that makes sense. My brain imagines that you said, “Wow! Did you see Collateral Damage? It’s really having an impact on our society!” My brain does this faster than you can remove your hand from a burning hotplate. So does yours. When you touch something unbearably hot, your hand jumps away even before your brain has a chance to realize you’re scalding yourself, right? The same thing is occurring here. Our brains convert the idiotic drivel flowing from each other’s mouths into sensible thoughts without even letting us know it’s happening!

This is important. Why? It’s important because it takes brain-power to do that conversion. You have lots of brain-power. You have so much brain-power that you hardly even use most of it. For all intents and purposes we can consider your brain-power unlimited. (The web standards project is trying to get people to follow the rules because computers do not have unlimited brain-power. It takes time and processing power away from other projects when your computer has to untangle poorly-written HTML. Get it?)

How does all this relate to comma use? Commas and semi-colons and parentheses — , ; ( ) — are logical operators in written English in much the same way that they are logical operators in mathematical expressions. Here is a list of people:

Jim, John, Jack, Jeff and Jeremy

The commas are there so we know that there is a separation between the items in the list. The “and” tells us that we are about to see the last item in the list. Correct?

NO!

You may want to think that that is what these mean. But you’d be incorrect. What has happened here? Why am I mad? Where is the problem?

The problem is that commas are required to separate each item in the list! There is no comma between Jeff and Jeremy. According to that list, Jeff and Jeremy are only one item. That list would look like this (to someone analyzing it properly):

  • Jim
  • John
  • Jack
  • Jeff and Jeremy

This might not seem important to you at all. But if this was a list of who was going to get an extra $100 in his paycheck, you can bet it would be important to Jeff and Jeremy. According to this list they are only going to get $50 while the other guys are getting $100. A list needs that last comma before the “and” (or before an “or”) to properly delimit the items at the end of the list.

Jim, John, Jack, Jeff, and Jeremy

The above example would let each guy get $100.

The cover of this week’s Sports Illustrated ignores this rule. Here’s what it says:

Living large and holding forth on everything from his golf, money and politics to Michael Jordan, TV Sports and Enron

The cover is describing the topic of an interview with Charles Barkley. This is misleading, though. This tells me that I am going to read about the topics in two lists:

  • golf
  • money and politics

and

  • Michael Jordan
  • TV Sports and Enron

The interview doesn’t devote more time to golf or Michael Jordan than it does to the combined topics of “money and politics” and “TV Sports and Enron”.

Get it? I know that the interview doesn’t devote more time to golf than it does to money and politics because I read the article. But if you’re designing the cover, do you want to depend on me to translate your bad grammar? Wouldn’t you rather make it easier for me to understand? I’m reading what you wrote. Why should it be my responsibilty to convert it into something meaningful? When people communicate it’s the responsibility of the person who wants to be understood to make himself clear. Why? If you expect people to understand you even if you don’t make sense, you have nobody to blame when you’re misunderstood but yourself.

But that’s just my opinion. If you disagree with me, tell me why. (Just remember that if I don’t understand you, though, it’s not my fault.) Maybe this is something that only really makes sense to computer programmers. A computer is not forgiving and I can get mad at it when it doesn’t understand what I’m trying to tell it. But won’t I sound pretty silly if I scream at the monitor for not understanding me?