This chapter discusses a number of arguments in favour of distinguishing a separate submodule that deals with subword structure within the syntactic macromodule, instead of seeing morphological structure as just a part of sentence-level syntactic structures. Arguments against deriving complex words via syntactic incorporation of heads into affixes include the impossibility of stranding syntactic material with the majority of affixes, the possibility of ‘incorporating’ adjuncts, and various lexical integrity effects that indicate syntactic operations cannot affect parts of complex words. In a module where the word-level and sentence-level structures are generated in separate submodules, these structures can only be connected by an operation that matches features in the node of one structure against corresponding features in a node of the other structure — an operation usually known as ‘insertion’. It is argued that this provides an explanation for why the observed effects of lexical integrity hold.
Keywords: morphology-syntax interface, incorporation, lexical integrity, submodule, subword, macromodule