The methodology and criteria of identification of Polish loanwords in Lithuanian
 The article examines the methodology and criteria of identification of Polish loan words in Lithuanian. Also etymology, peculiar developments, and trends in the infiltration of these borrowings are discussed. The following conclusions are proposed based on our analysis: 1) Polonisms in Lithuanian can be divided into three groups, based on the principles of (α) establishing the primary source of the variants of the Lithuanian word (through areal distribution), and (β) the words’ phonetic, morphological and semantic identity (correlated with the modulation of α). Also taken into account are peculiarities in the usage of the primary forms (not necessarily in the inherited layer) on the West Slavic ground, and their secondary variants in the East Slavic languages (based on the influence of factors α and β). The resulting three groups are: I. mo n o g e n i c (i.e. homogenous, not represented in the vocabulary of the East Slavic languages (based on factor α)), II. i n d e t e r m i n a t e (due to the presence of variants of loanwords from Polish in East Slavic vocabulary (factor α) in different time periods), III. a l t e r n a t i v e (III.1. forms belonging to the inherited layer, characteristic of Polish and one of the East Slavic languages (with regard to factor α); III.2. doublet variants of foreign origin, derived from a different primary source; III.3. Semipolonisms). 2) The kg digraph is one of the crucial characteristics that allows Polish loanwords in Lithuanian to be divided into the monogenic, indeterminate, and alternative. It is attested in the structure of Old Belorussian lexemes, and it reflects the phonetic feature of the Belorussian explosive velar consonant г /g/ in loanwords and in words of the inherited layer, in combinations with other consonants: зг, дзг, and джг. 3) Spirantization of the West Slavic sonant *ȓ (> ř /ź/ or /ś/), when the temporal factor is taken into account (the process operated till the 17th c.), is a feature of paramount importance as it allows Lithuanian words to be identified and attributed to either Polish or Belorussian. 4) The phenomenon of vocalization of the Polish lateral sonant ł (the shift to /ṷ/), also known as vavation, is reflected in those loanwords in Lithuanian which belong to a later period, in dialectal forms, and also in Belorussian lexemes, and it regulates the division of borrowings into Polonisms and Belorussianisms. 5) When attributing loanwords based on differences in vowels, it is their place in the system that should be considered, not their pronunciation. 6) The etymological status of the borrowing is determined by a match between the semantic value of the word in Lithuanian, and the original form in the West and/or East Slavic languages. 7) The fact that the Polish etymon is itself of East Slavic origin, has no influence on the establishing of the status of Polonism for a borrowing into Lithuanian (so-called secondary Polonisms).