A colleague asked me about a grammatical judgement someone had questioned her on: a sentence of the type “There is to be no swinging the legs back, no leaning forward, no pushing down on the feet.” Surely it should be “There are to be…” said the person, because there are three things named. My colleague knew well that it’s is – if you use your native-speaker reflex, that’s the choice you’ll make unless you second-guess yourself – but there’s always the matter of explaining why.
Well, here’s a quick analysis of why. It has to do with no and the number it negates. Have a look at some sentences that most native speakers would find idiomatic (they all work without the to be as well):
“There are to be no flowers.” → negating plural
“There is to be no gardener.” → negating singular countable
“There is to be no water.” → negating mass object, which is treated as singular because it’s not plural (singular is the default in English and plural is the “marked” option)
“There is to be no watering the flowers.” → negating gerund representation of action, which is inflectionally the same as a mass object because it’s not plural
“There is to be no water and no wine.” → negating mass and mass, which is still mass and thus still singular (absence of mass is absence of mass; nothing plus nothing is still nothing)
“There is to be no watering the flowers and no drinking the wine.” → as in the previous one, singular because unmarked (equivalent to mass objects – no specification of plural number)
“There is to be no gardener and no bartender.” → distributively negating non-plural objects; compare “There are to be no gardener and no bartender” or “There are no gardener and no bartender,” which may sound not quite right
“There are to be no flowers and no water.” → may seem weird because it’s conflicting in number
“There is to be no water and no flowers.” → also weird, but possibly more acceptable because we default to the singular on existential predicates (why we often say “There’s flowers on the table” when formally it’s “There are flowers on the table”)
So negation of a mass object is a mass negation, and as such takes the singular, and negation of multiple gerunds is also by default singular because it doesn’t specify plural and because in any case it would get the distributive singular. It only gets plural if it is specified to plural (“There are to be no swingings back of the legs”).
The “There are to be…” thought is clearly an example of overthinking. It’s false agreement, because although there are multiple noun phrases, the agreement is with not the quantity of noun phrases but the quantity signified by them. A native speaker’s ear will normally by reflex give the singular, but we override that reflex if we overthink. It’s like thinking too hard about the muscles used in standing up: swinging the legs back, leaning forward, pushing down on the feet… you may end up stuck in your chair until you stop overanalyzing it.
If you’re interested on more on there is versus there are, by the way, I’ve covered the topic a couple of times, once on this site in “There’s a couple of things about this…” and once for The Week in “There’s a number of reasons the grammar of this headline could infuriate you” (their title!).