Speech is the vocal conduct of sense-making processes that involve both an external receiver (the hearer) and the speaker envisaged as an internal receiver: to speak is to cause one(self) to experience the emergence of organized thinking formatted by verbal patterns. Syntax is defined as a series of operational templates to be coupled with lexical selections to form phrases, following language-specific ritual syntactic agendas such as the subjet-predicate pair. However it is possible to decide at any moment of the execution of this process to go on following the structural beaten track or to open up new ones in the form of adverbials, subordinate clauses, insertions and so on. In this respect, prosody plays a metasyntactic role: prosodic events are the signature of metasyntactic decisions in real time and they "inform" both the interpreting hearer and the speaker himself, who realies on the symptoms of his own action to keep track of the ongoing developments. Prosody plays an ambiguous role that is both semiotic (forming a conventional sign system) and symptomatic (the corporal manifestation of psychological events of subjective, intersubjective and metasyntactic nature), which makes it possible to sketch an integrated model of the role and effects of prosody in spontaneous speech.