Sobin (2003) discusses some interesting examples of negative inversion that appear to have an adverbial in between the negative constituent and the inverted auxiliary. His three examples follow:
(1) I promise that on no account during the holidays will I write a paper.
(2) I promise that under no circumstances during the holidays will I write a paper.
(3) Never again over Christmas will I eat that much turkey.
(This type of sentences appears to have first been noticed by Haegeman and Gueron 1999 and Haegeman 2000.)
Sobin uses these examples to argue against most accounts of negative inversion, which have the auxiliary fronting across the subject, while the subject is in its normal position (Spec-TP). Instead, he suggests that negative inversion has the subject staying low, below T, while the auxiliary is in T and the negative constituent is in a higher projection (Spec-NegP). The adverbial in between is adjoined to TP.
An alternative that Sobin does not consider, however, is that the negative expression and the adverbial are a single constituent. This possibility is suggested by data in Haegeman 2000 (although Haegeman herself never adopts this position). Haegeman likens the above examples to wh-questions like the following:
(4) Under what circumstances during the holidays would you go in to the office?
The adverbial here clearly forms a constituent with the wh-phrase, since it can move long-distance with it:
(5) Under what circumstances during the holidays did you say that you would go in to the office?
Additionally, "under what circumstances" and "during the holidays" can combine semantically, quantifying over situations in certain time intervals.
I will argue that Sobin's examples (the three above are all that he provides) all involve a single constituent, and so Sobin's conclusions regarding negative inversion do not follow.
First, phrases like those in all of Sobin's examples can move as a single constituent. Corresponding to (1) is (6); (4) and (5) correspond to (2); and (7) corresponds to (3):
(6) On what account during the holidays did you say that you will write a paper?
(4 and 5 correspond to 2)
(7) How many times over Christmas did you say that you ate too much turkey? (Answer: I said that I ate too much turkey three times over Christmas.)
Second, and most tellingly, adverbial expressions that can be adjoined to TP (on standard assumptions, since they appear between the complementizer that and the subject) but cannot form single constituents with a negative expression are incompatible with negative inversion in their pre-subject position:
(8) He bragged that with a quill pen he could write a paper.
(9) I promise that on no account will I write a paper with a quill pen.
(10) *I promise that on no account with a quill pen will I write a paper.
(11)*On what account with a quill pen will you write a paper?
Note that they cannot be fronted with wh-phrases, either (11). More examples follow, in the same order in each set:
(12) I said that over Christmas I would eat only one type of turkey.
(13) I said that only one type of turkey would I eat over Christmas.
(14) *I said that only one type of turkey over Christmas would I eat.
(15) *What type of turkey over Christmas will you eat?
(16) I said that on Friday I could not find a word about Smith's negativity.
(17) Not a word could I find on Friday about Smith's negativity. (found on web)
(18) *Not a word on Friday could I find about Smith's negativity.
(19) *How many words on Friday could you find?
(20) She said that in front of her house she will not plant any trees.
(21) Under no circumstances will she plant trees in front of her house.
(22) *Under no circumstances in front of her house will she plant trees.
(23) *Under what circumstances in front of her house will she plant trees?
(24) I promise that on that topic I will never write a paper.
(25) I promise that on no account will I write a paper on that topic.
(26) *I promise that on no account on that topic will I write a paper.
(27) *On what account on that topic will you write a paper?
(28) I said that on Friday I remembered to bring a penny.
(29) Not a penny did I remember to bring. (Sobin's ex 2, from a reviewer)
(30) *Not a penny on Friday did I remember to bring.
(31) *Which penny on Friday did you remember to bring?
This is surprising on Sobin's account: any adverbial that can adjoin to TP should be able to appear between a fronted negative expression and the auxiliary in T.
Finally, sentence (1) gets worse when "on no account" is changed to "on no one's account"; the corresponding wh-phrase gets worse in the same way:
(32) I promise that on no one's account will I write a paper during the holidays.
(33) *I promise that on no one's account during the holidays will I write a paper.
(34) *On whose account during the holidays will you write a paper?
This seems to be because "on what account during the holidays" makes sense as a semantic unit, but "on whose account during the holidays" does not. In Sobin's three examples (1-3), the negative expression plus the adverbial together are a single unit quantifying over time intervals. This could not be the case in any of the examples I have provided, and so the negative expression and the adverbial cannot be a single constituent.
I conclude that Sobin's very limited examples all involve a single constituent before the auxiliary. Therefore, none of Sobin's conclusions regarding negative inversion follow. Material before the auxiliary is (and must be) a single constituent, and probably occupies the specifier of whatever projection the auxiliary is the head of. There is no reason to think that the subject is not in its normal position. (One final note: while I am claiming this is true for negative inversion and for the examples of wh-questions given here, it is probably not true for all cases of a wh-phrase followed by some kind of adverbial and then the inverted auxiliary. Haegeman 2000 gives some examples of wh-questions that have this form but where the adverbial is probably not part of a constituent with the wh-phrase. Additionally, a wh-phrase can be followed by a negative constituent, which is then followed by the auxiliary; see Maekawa 2006.)
Haegeman, Liliane (2000). Inversion, Non-Adjacent Inversion, and Adjuncts in CP. Transactions of the Philological Society 98: 121-160.
Haegeman, Liliane and Jacqueline Gueron (1999). English Grammar. Oxford: Blackwell.
Maekawa, Takafumi (2006). Configurational and Linearization-Based Approaches to Negative Inversion. In O. Bonami and P. Cabredo Hofherr (eds.), Empirical Issues in Syntax and Semantics 6, pp.227-247. (available at http://www.cssp.cnrs.fr/eiss6/maekawa-eiss6.pdf)
Sobin, Nicholas (2003). Negative Inversion as Nonmovement. Syntax 6: 183-212.