Trasianka is a mixed form of speech in which Belarussian and Russian languages structures and words are used. Following the Wikipedia information about 16,1 % of Belarussians use regularly trasianka (It's about 1.6-2 million people). To recognise the linguistic status of trasianka, in the years 2008-2013, a research project carried out by linguists and social scientists at the University of Oldenburg (in cooperation with partners from the Belarusian State University in Minsk) created two bodies of oral texts in the mixed speech. It will be used as tha base for the treebank