Q: New York’s MTA uses a construct I haven’t noticed elsewhere: “There is no F train service between West 4th St. and 42nd St. in both directions.” Standard usage, in my book, would be “in either direction.” Is this usage unique to the MTA? Or is it common transit-speak?
A: No, the usage isn’t unique to the Metropolitan Transportation Authority.
This is from a tweet by Transport for London about problems on the Central line: “No service in both directions btn Liverpool St & Leytonstone.
And here’s a Twitter example from Bay Area Rapid Transit in San Francisco: “No service between 24th-Colma in both directions due to downed tree near Balboa Park.”
The usage may be more common in New York than elsewhere, but not every MTA announcer uses it.
A New York Times reader noted in a contribution to Metropolitan Diary a few years ago that “to my surprise and delight, I heard, ‘There is no service on the N train in either direction.’ ”
And a search online of MTA announcements found a dozen or so of “either” examples, including these:
“No N or R trains in either direction at Jay Street-MetroTech, Court Street, Whitehall Street, Rector Street, Cortlandt Street and City Hall” (Jan. 30, 2014).
“There will be no D service in either direction at 205th Street, Bedford Park Blvd, Kingsbridge Road, Fordham Road, 182nd-183rd Sts, Tremont Avenue, 174th-175th Sts, 170th Street and 167th Street.” (July 12, 2013)
“From 11:30 p.m. Friday, March 11 to 5 a.m. Monday, March 14, there are no Q trains between 57th Street/7th Avenue and Prospect Park in either direction due to BMT track tunnel inspection and structural repair and track and switch work north of Atlantic Avenue” (March 10, 2011).
Is the use of “both” in your example wrong? Well, we find it unidiomatic, but not ungrammatical. And we couldn’t find a single grammar book or usage manual that objects to it.
We did, however, find two grammar books that specifically criticize the use of “both” with a negative verb, though not in other negative constructions.
In your example (“There is no F train service between West 4th Street and 42nd Street in both directions”), a positive verb (“is”) refers to a negative phrase (“no F train service”).
If it had a negative verb (“There isn’t F train service between West 4th Street and 42nd Street in both directions”), the usage would be more questionable.
Those train-service announcements are hard to misunderstand. But some similar constructions could be confusing.
For instance, a sentence like “Both children didn’t get measles” defies an accurate interpretation. Did both fail to catch the disease? Or did the disease strike just one, not both?
We were surprised that we couldn’t find more objections to the use of “both” with a negative verb. Apparently most language writers aren’t troubled by it—or aren’t troubled enough to write about it. Here are the two objections we found.
The “both” entry in English Grammar Today says: “We don’t use both with a negative verb; we use either instead: There was not a considerable difference in percentages for either sex in terms of having a Bachelor’s degree.”
However, the grammar guide, by Ronald Carter, Michael McCarthy, Geraldine Mark, and Anne O’Keeffe, is intended for the general reader, and doesn’t offer a reason for its objection.
The Cambridge Grammar of the English Language, a more scholarly reference, says “either” is “strongly preferred” over “both” in sentences with a negative verb. As an example, it cites “He hadn’t eaten either of the pies” as preferable to “He hadn’t eaten both of the pies.”
The Cambridge authors, Rodney Huddleston and Geoffrey K. Pullum, describe “both” as a “universal quantifier,” a term that expresses all of a quantity, and “either” as an “existential quantifier,” which expresses some of a quantity.
The authors compare “both” to “all,” another universal quantifier, and “either” to “some,” an existential quantifier.
Huddleston and Pullum consider their “both” example above ambiguous, since it could mean that no pies at all were eaten, or only one.
It’s easier to see this with the use of “all” and a negative verb. In Woe Is I, Pat’s grammar and usage book, she uses this sentence as an example: “All Swedes are not blond.”
“To say, All Swedes are not blond, is to say that not a single Swede has golden hair,” Pat writes. Her advice is to negate the “all,” not the verb: “Use not all instead: Not all Swedes are blond.” (We have to admit, however, that not every reader would give that sentence such a literal reading.)
In The Writer’s Art (1984), James J. Kilpatrick says constructions with “every,” “everyone,” and “everything” present a similar problem. He quotes the advice columnist Ann Landers: “Everyone in San Francisco is not gay.” Putting the “not” first solves the problem.
from Grammarphobia http://www.grammarphobia.com/blog/2017/06/both-either.html