My class stumped me today with a GMAT sentence correction question involving not … until. I ended up delving into the Cambridge Grammar of the English Language, and here is my tentative explanation:
Until marks the “endpoint” of an action or state, and it can be a preposition or conjunction:
(1) I played the piano until I was 12 years ago.
(=I stopped playing the piano when I was 12; you don’t know when I started.(2) The cafeteria is open until 6pm.
(=The cafeteria closes at 6pm.)
It is not easy to move until 6pm to the front of sentence (2) (?”from 6pm, the cafeteria is open”) because until 6pm completes the meaning of is open, and so has to come after it. To put it another way, until 6pm is an adverbial expression of time that modifies “is open”, not the entire sentence, so it needs to come after the verb.
However, when the clause is negative, the meaning is more complex. Here is the example from CGEL:
(3) I didn’t notice my error until later.
(=I only noticed my error later)
There is no positive version of this sentence (*”I noticed my error until later” is ungrammatical). The adverbial until later tells us “how long this negative state of affairs lasted.” That is, not … until tells us when something started happening. You can’t move it to the start of the sentence because is modifies the verb, by telling us when the negative (didn’t notice) stopped being true.
So, in the class example from the GMAT practice book (I’m paraphrasing):
(4) Scholars did not begin to study Native American poetry until 1900.
(=Scholars began studying Native American poetry in 1900.)
Since the adverbial (since 1900) is part of the verb “did not begin”, it cannot simply be moved to the start of the sentence. (On the other hand, we can say: After 1900, scholars began studying poetry because “after 1900” modifies the entire clause.)
However, it is possible to move any element to the front using an it cleft. The negative (not) needs to move with until because they create the meaning of a starting point together:
(5) It was not until 1900 that scholars began studying …
Please post questions or other examples!
Reference: Huddleston & Pullum, Cambridge Grammar of the English Language (Cambridge University Press, 2002).
Nigel Caplan 
Sorry Nigel, but I would analyse “The cafeteria is open until 6pm” slightly differently to you. I see the expression “open until 6pm” as an adjectival phrase, headed by the adjective ‘open’, functioning as predicative complement to ‘be’. “Until 6pm” is a preposition phrase, headed by the temporal preposition ‘until’, which is functioning as complement to ‘open”. Expressions that complete’ the meaning of verbs, nouns and adjectives are not modifiers (such as adverbials) but complements.
Bill,
Thank you for this clarification. CGEL distinguishes between complements and adjuncts, and yes I agree that “open until 6pm” makes more sense as a complement structure.
My problem was trying to explain sentence (4) to my class, where “until” is clearly an adjunct. CGEL explains that the adjunct has scope over the negative verb (I’m paraphrasing — I don’t actually carry the book around with me!). I presume this is why it can’t move to another slot in the sentence with causing other elements to shift too. Does this sound right?
#2: “Until 6PM the park (cafeteria) is open. To stay later you will need a special permit.”
What section in the CGEL (2002, reprinted with corrections 2008) are you referring to? Is it page 706 in Chapter 8, section 7.3 “Bounding duration elements”?
I’m not sure I’m getting what it is that the students were supposed to be doing with your “GMAT sentence correction question” (similar to #4) . . . ?
#4 A (original) : Scholars did not begin to study Native American poetry until 1900.
#4 B: Scholars did not, until 1900, begin to study Native American poetry. (Probably bad.)
#4 C: Until 1900, scholars did not begin to study Native American poetry.
#4 D: Not until 1900 did scholars begin to study Native American poetry.
I think #4C is okay, merely moving the adjunct to the front (preposing). But then there is that “word weirding” effect, which often happens when one examines a piece of prose too much. 🙂
At first, I thought the phrase “begin to” would make #4C be awkward or ungrammatical. And that the sentence would work without it. But then, I noticed that by adding that phrase, the speaker is then able to emphasize his point even more.
#4 C1: Until 1900, scholars did not study Native American poetry. (okay)
#4 C: Until 1900, scholars did not BEGIN to study Native American poetry. (Emphasis, as in speech. This might/probably be okay.)
#4 C2: Until 1900, scholars did not EVEN begin to study Native American poetry. (Gives more emphasis, as in speech. I think this is okay.)
“Until 1900, everyone thought the world was flat. After 1900, everyone thought the world was round. Today, we all know better.”