This paper investigates the morpho-phonological differences
between the members of related noun-verb pairs in Catalan Sign Language. Like
parallel investigations in other sign languages, our experimental work provides
evidence that the major differentiating factors between related nouns and verbs
materialize in the movement component of signs and non-manual markers, thus
providing empirical support to the hypothesis that most noun-verb pairs have
different morpho-phonological properties. We distinguish different types of
movements, which we categorize into four regular morphological subgroups. We
also take into account a fifth group that shows no apparent movement
distinction. Concerning non-manual markers, we provide empirical evidence that
nouns are mostly produced simultaneously with mouthing, in contrast to verbs,
which in a smaller proportion are produced mainly with mouth gestures.
Crucially, the fifth group presents the largest ratio of mouthing for nouns and
even for verbs. We address these findings within an exo-skeletal theoretical
syntactic approach (Borer 2005a,b, 2013, 2014).