The notion of 'compounded word / compounding' has been a central topic of the recent literature on morphology, but is still lacking a universally accepted definition: in fact, almost all the definitions we find in the literature appear unsatisfactory since they tend to label as compound any multi-word lexical item or to exclude from the category 'compounding' lexical items which, on the contrary, seem to match the necessary conditions for being members of it. Moreover, the category 'compounding' crosses the limit between morphology and syntax. All these problems have made difficult both a definition and a classification of compounds. In this paper, I aim both to draw a new definition of compounding, based only on morphological criteria, and to sketch a new classification of compounds, starting from the distinction between coordinative compounds and hierarchical compounds. In the last section of the paper, a comparative analysis of English end Italian verbal compounds will be made, in order to show that items which belong to the same semantic class can exhibit relevant differences on the formal ground in a cross-linguistic perspective.
