In this paper, we examine some basic linguistic abilities in a small
sample of adults with minimal receptive vocabulary, whose receptive
mental verbal age ranges from 1;2 to 3;10. In particular, we examine
whether the participants in our study understand noun phrases consisting
of a noun modified by an adjective. We use stimuli that they can
recognise by name. Except for one participant, we find that, while all of
them understand the noun and adjective in isolation, none seems to
understand these noun phrases, which means that they seem to not
do linguistic composition. In order to test whether the difficulty is
linguistic or conceptual, we ran two other studies, one on concept
composition, and the other on iconic symbolic composition (composition
of pictograms). Results suggest that linguistic composition is
particularly difficult in this population, and that vocabulary breadth
may not predict compositional abilities
