This paper provides an account of a research project carried out on a multilingual corpus containing conversations that have been recorded in the bilingual region of South Tyrol, Italy. The study offers an analysis of its quantitative and qualitative distribution of languages. Moreover, it aims to shed some light on any parameter that can contribute to classify interactions according to their degree and type of bilingualism. The results of this investigation, which is based on several samples of speech, reveal that the relative frequency of parts of speech can be used to this end.