The text discusses words occurring in the Polish-East Slavic borderlands and prevalent in eastern Polish dialects. Differntiation between old references and loans in this area is not always easy. The material presented here is very diverse. In the case of certain words, identifying them as East Slavic loans with an indisputable source is possible, while in the case of others it is difficult to identify the direct source of the loan. Among the words recorded in the East Slavic borderlands we can find those whose range in Polish dialects seems to indicate the possibility of Ruthenian influence; however, their Polish phonetic form implies their native origin and one should speak about an old reference in this respect. We also encounter Pan-Slavic words, where a doubt arises as to whether they are loans or old references in Polish in the East Slavic area and Eastern Poland.

The text discusses the question of Polish and Eastern Slavic origin of the words: (h)uzer, uzior ‘lower part of a sheaf of corn’, huzica ‘bird's rump’, huzno ‘bird's rump’. The relic forms of words * gǫzyrь, * gǫzerь with a nasal vowel can be found in the dialects of Southern Borderlands and in Chełm region. In this area they were originally shared by Polish and Ruthenian languages. Forms containing u: * guzуrь, * guzerь appearing in the Polish language should be ascribed to the mutual impact of Ruthenian languages, even though they may have been originally Polish, too. The influence of the Ruthenian language is evident in the commonplace h‑ (< g) in word‑initial position, e.g. huzno, huzica, huzer, huzir, etc., as well as in infrequent shift towards u̯ and v, e.g. u̯uźor, u̯uźoro, vuźur. The occasional g in Eastern Slavic vernacular languages of the Białystok region – guzerye, due to the opaque formation, does not seem a manifestation of phonetic Polonization.

The article is a successive part of the considerations on language contacts in relation to lexis. Analysed are words characteristic of the Polish‑Eastern Slavic borderland, where it is difficult to unequivocally decide whether they are borrowings, references, or examples of the shared Slavic heritage. The following names were interpreted in this respect: binduga ‘a place by the river where wood is deposited for floating, rafts are made and launched’, chaszcze ‘thicket, bushes, scrub’, chudoba ‘livestock’, chusta ‘a sheet of linen or other clothing fabric’, chusty ‘linen (to be washed)’; chołosznie ‘trousers’, kołosza, chołosza ‘trouser leg’, łukno and ustaw ‘vessels for honey storage’ and at the same time ‘units of measurement of honey’, miękiny ‘chaff’, miękuszka ‘bread pupl’; nawleczka, nawłoka, nawłoczka ‘pillowcase, duvet cover’, ‘furniture cover’; niewiasta, niewiastka ‘daughter‑in‑law’, żmykać ‘hand‑wash’. A detailed tracing of the geography, development of individual forms, directions of the inflow of words discussed in the text shows the multiplicity of ways in which individual lexical items penetrate borderland dialect systems. The most interesting examples are those in which the same development outcome is triggered by completely different phonetic processes.

The article deals with the question of linguistic interference among Slavic languages at the example of Choroszczynka, a bilingual village in Biała Podlaska County, Lublin Voivodeship. The presentation of two complete questionnaires for the Slavic Linguistic Atlas (OLA), Polish and Ukrainian, not only makes it possible to capture grammatical and lexical peculiarities of both sets assigned to individual dialects, but also reveals carelessness of the fi eldworkers who collected the data. This, in turn, contributed to such an interpretation of dialectal data presented in OLA maps which does not refl ect linguistic reality.