The aim of the paper is to explore two sandhi phenomena of r-zero alternation, i.e. linking and intrusive r. We address the question of lexical representation of etymologically r-less and r-full forms participating in the processes. Moreover, we discuss the influence of historical r on both vowel quality and quantity and explain some developments of etymologically r-full forms which have led both to the confined distribution of r and various vocalic reflexes in non-rhotic dialects.