||The Thesis deals with the acquisition of vocabulary in the period of advanced language development in second-level primary school pupils from different socio-economic and socio- cultural backgrounds. The theoretical section summarises the basic findings as well as the existing empirical research, focusing in particular on the influence of the family environment of the individual on his/her linguistic development. It provides a complex picture of the education of Roma children in the Czech Republic at this point in time. The investigative section presents independent research into the vocabulary of pupils, with regard to selected word groups in the acquisition corpus SKRIPT2015. The texts of pupils attending schools in socially-deprived areas, or in areas under threat of social deprivation and with a strong Roma presence, are compared with the texts of pupils attending average schools. On the basis of this comparison, a picture emerges of the impact of different socio-economic and socio-cultural environments on the written language of pupils, as well as the effectiveness (or lack thereof) of the existing support mechanisms provided by educational institutions.