Originally published in Active Voice, the magazine of the Editors’ Association of Canada
About this sentence that you’re reading…
Should that be “About this sentence, which you’re reading”? After all, you’re not reading any other sentence, are you? So it’s not restrictive, so it must be non-restrictive, meaning it should have a comma and use which. Right?
I was talking to my wife Aina and a friend about this the other day…
What do you mean, how many wives do I have? Look, if I set it off in commas, it would be “I was talking to my wife, Aina, and a friend about this the other day,” and you would be saying “So that’s three people? Who’s your wife if not Aina?”
Since you’re an editor, you’ve heard of restrictive and nonrestrictive clauses. A nonrestrictive clause is like a little Santa Claus in the sentence: it gives the reader a gift, with a comma or two as tiny ribbons.
The cakes are served warm.
The cakes, which are kept in the refrigerator but carried under the waiters’ arms, are served warm.
The sentence would be coherent without it, but it’s there as a special bonus of information. It’s also called a nonrestrictive relative, which works because it’s not really Santa Claus giving you gifts, it’s your relatives. (The rules apply similarly to non-clause modifiers as well, such as the name of my wife, Aina.)
A restrictive clause or relative (or modifier) is like your aunt who says “I’m giving you anything you want as long as it’s this sweater!” It no sooner gives than it starts to take away.
The tea is served cold.
The tea that is carried by Pat is served cold; the tea that is carried by Alex is served warm.
But where there is a Claus, there may be a Grinch. What is a restrictive Grinch? It’s one of those people who carp at things that are perfectly clear to reasonable people. Consider:
He went to a famous school called Eton.
The restrictive Grinch might say “Oh, so there are multiple famous schools called Eton?” In fact, the sentence does not necessarily imply that there are multiple famous schools called Eton (although it does imply that there are multiple famous schools), and ambiguity is not automatically a grammatical error – although it can be worth avoiding… when a reasonable person might reasonably misread it, or when too many people might deliberately (and unreasonably) misread it for their own entertainment.
Reasonableness is important. Communication normally (outside of contracts and courts of law) depends on people being reasonable. We make inferences on the basis of what’s reasonable, given our knowledge of the world. If we have some new data, such as a sentence,* and we choose among different interpretations on the basis of what we already know to be the case, we’re using a loose form of Bayesian inference.
Let’s take a Bayesian look at “my wife Aina and a friend” versus “my wife, Aina, and a friend.” In the version with commas, if we don’t know my wife’s name, we need to conjecture or determine whether I use the serial comma; if I don’t, it’s clearly two people, but if I do, it may be three. In the version without commas, the possibilities are (1) that I have more than one wife or (2) that I am disregarding the usual rule about setting off nonrestrictives with commas. Why would I disregard it? To avoid interrupting the flow or causing ambiguity with the extra commas. Given that bigamy is illegal in our society, option 2 is far more likely. Indeed, only a restrictive Grinch would raise the objection that the comma-free version must mean option 1.
There are, of course, many cases where proper use of commas is necessary to set off nonrestrictive clauses for clarity or legal defensibility. But there are also cases where the commas make no difference to the meaning but may make a difference to the flow or tone. The moon, which orbits the earth, is also the moon that orbits the earth (since there are many moons but there is one we call the moon); the sun, which we orbit, is also the sun that we orbit (for the same reason). This sentence that you’re reading is this sentence, which you’re reading, and the different possible uses of this make both defensible, but flow and tone may make one a better choice than the other.
So, when we are faced with a modifier such as a relative clause and we’re not confident about whether it’s restrictive or unrestrictive, we should ask the following questions:
- Will the commas help or hurt the flow?
- How likely is it to be misread accidentally?
- How likely is it to be misread deliberately?
- By which readers?
- And do they really matter?
- By which readers?
*Or some new data such as a sentence – equally true.