Back on the best holiday of the year, Mark Liberman [wrote](http://languagelog.ldc.upenn.edu/nll/?p=322) on LL about some strange claims about the constituency and plurality of _a million dollars_. In a comment, I noted some perhaps genuinely-strange uses of “a,” leading to [this follow-up](http://languagelog.ldc.upenn.edu/nll/?p=330#). Having had [the fear of Zwicky](http://languagelog.ldc.upenn.edu/nll/?p=327) etched into my brain, I thought I would avoid a too-long comment and just talk about it here.
First, the sentences:
> He was there for a good seven years.
> An additional three people are required.
> A mere four nations recognize that standard.
> She collected an amazing and heretofore unprecedented forty million dollars.
What we have is “a” and then some adjective phrase, and then a quantified nominal. There are some interesting questions to be asked: first, what is the range of adjectives? It seems sort of limited: _a grueling 100 miles_, but ?_an asphalt-paved 100 miles_. All the examples given so far involve some sort of “evaluation” (shock, amazement, disappointment, unprecedentedness, etc.). Maybe someone nice will do a corpus study and report the findings (and of no one does it soon, I might just have to).
Next question: does the whole thing act as a singular or plural phrase, for the purposes of subject-verb agreement? The comments seem to show that, depending on the “context” (how the NP is construed semantically, let’s say – either as a divisible group of individuals or as a lump), you might get singular or plural agreement.
> A good 100 people have/*has arrived.
> A mere four nations recognize/*recognizes that standard.
> A mere four nations is/are not enough