The article 'a(n)' in English quantifying expressions: A default marker of cardinality

Certain English quantificational expressions feature what appears to be an indefinite article, e.g. 'a bunch, a few, a hundred'. These can be divided into three types of quantifying expressions: pseudopartitives ('a lot, a bunch, a ton'), article-requiring quantifiers ('a few, a couple, a hundred'), and article-free quantifiers ('three, many, several'); article-free quantifiers have an article under certain circumstances, e.g. modification by an adjective ('a surprising 30 …'). While standard analyses would take the article in these expressions to be a D head, it is argued here that the article is not in D, nor is it singular or count, as evidenced by its (lack of an) interaction with verbal agreement. Instead, it is claimed that 'a(n)' is a default cardinality marker, which surfaces when a QP is present, but fails to be spelled-out by other material. The distribution of default 'a(n)' further interacts with adjective placement ('a surprising 30'), plural marking on some quantifiers ('tons of'), other determiners ('the hundred'), and the functional status of the quantifier ('a wealth of' vs. 'a lot'). The resemblance of this article to the English indefinite article 'a(n)' is also considered, and a possible unifying analysis is given