abstract:The discussion focuses on the problem of pre-Celtic substratum languages in the British Islands. The article by R. Matasović begins by dealing with the syntactic features of Insular Celtic languages (Brittonic and Goidelic): the author analyses numerous innovations in Insular Celtic and finds certain parallels in languages of the Afro-Asiatic macrofamily. The second part of his paper contains the analysis of that particular part of the Celtic lexicon which cannot be attributed to the PIE layer. A number of words for which only a substratum origin can be assumed is attested only in Brittonic and Goidelic. The author proposes to reconstruct Proto-Insular Celtic forms for this section of the vocabulary. This idea encounters objections from T. Mikhailova, who prefers to qualify common non-Celtic lexicon of Goidelic and Brittonic as parallel loanwords from the same substratum language. The genetic value of this language, however, remains enigmatic for both authors.