The Grammarphobia Blog

Please be careful of the gap!

Q: I’ve been bothered by a usage in the MTA’s automated subway announcement at certain stations (e.g., 14th St.-Union Square): “please be careful of the gap.” One can be plain careful and one can be careful to do or not to do something. But can one be careful of something? Mindful, yes (and that’s presumably what the MTA meant).

A: In some New York City train stations, there’s a gap between the car and the edge of the platform—a nasty hazard for the unwary. The same is true in London.

In New York, subway riders are told to “be careful of the gap.” But in London, riders of the underground are told to “mind the gap.”

In both cities it’s good advice, given in good English.

The Metropolitan Transportation Authority could have used the word “mindful” instead, but there’s nothing wrong in its telling people to “please be careful of the gap.”

The phrase “be careful” doesn’t have to be followed by the preposition “to” plus an infinitive, as in these examples: “be careful to cross at the light” … “be careful not to fall” … “be careful to ask permission first.”

It can be followed by other prepositions: “be careful of the eggs” … “be careful around the baby” … “be careful with knives.” This is how “be careful” is used in that subway announcement.

“Be careful” can also be followed by “that” (“be careful that no errors creep in”). And, as you know, the adjective “careful” can be followed by a noun (“a careful surgeon”).

Like most English words, “careful” has undergone some changes over the centuries. When first recorded, in Old English, it had meanings that are no longer used today.

For one thing, it meant “full of grief; mournful, sorrowful,” the Oxford English Dictionary says. For another, “careful” meant “full of care, trouble, anxiety, or concern.”

So in the very distant past, “careful cries” were cries of grief or sorrow; a “careful widow” was a mourning one; a “careful brow” was a troubled brow. In those days, people didn’t tell each other to “be careful.”

Today they do, because “careful” roughly means attentive, painstaking, watchful, cautious, exercising or taking care, and so on.

Though a couple of isolated uses were recorded in the 11th century, examples of the newer meanings didn’t appear in significant numbers until the 16th century.

In its newer incarnations, “careful” is often followed by a preposition. The OED says the word can mean “full of care or concern for, attentive to the interests of, taking good care of, and so on (the preposition that follow are shown in italics).

Here’s an example of a “careful of,” cited by the OED: “Be careful of the horses, Sam … don’t ride them too fast” (from Uncle Tom’s Cabin, by Harriet Beecher Stowe, 1852).

And as we’ve said, “careful” can also be followed by “that” as well as by infinitive phrases. Here are examples of each:

“Be careful that they are neither thrown about nor changed” (from Hoyle’s Games Improved, 1820).

“Both males and females are careful to ornament their persons with paint” (from William Macgillivray’s The Travels and Researches of Alexander von Humboldt, 1836).

So “careful of” is a well established English usage. The MTA uses the phrase not only in its recorded announcements but also on its website.

On a page entitled “How to Ride the Subway,” the transportation agency says, “Be careful of the gap between the platform and the train.”

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