Two experiments examined English speakers' choices of count or mass compatible frames for nouns varying in imageability (concrete, abstract) and noun class (count, mass). Pairing preferences with equative ("much/many") and non-equative ("less/fewer") constructions were compared for groups of teenagers, young adults, and older adults. Deviations from normative usage were, for all ages, larger for count than for mass nouns, for the non-equative than for the equative construction, and for abstract count than for concrete count nouns. These results indicate that mass syntax is not a developmental default, support proposals that mass syntax is more flexible than count syntax, verify the non-prescriptive use of less with count nouns, and extend the interaction of syntax and semantics in noun classification to older ages, with older adults showing a reduced reliance on semantics. Knowledge of frame compatibility and knowledge of noun class are also shown to be largely independent.