The paper presents research based on Modern Greek corpora with a view to investigate optional vowel deletion in different genres. The preverbial pairs θα – θ’ and να – ν’ were examined and it was found that the phenomenon does not absolutely prevail, nor is it absent from all genres, but variational tendencies are observed. Reduced forms predominate in literary texts, as well as in informational (humanities) texts published in a book. By contrast, law and administration texts have very few reduced forms. In all other texts, the entire forms are the norm, although their occurrence differs: in humanities and social sciences texts the percentage is relatively low, while it is higher in economics texts and even more so in science texts. An important finding concerns the role of the means of publication, which is crucial as far as phonological phenomena are concerned; thus, academic and information texts have less reduced forms, when they are published in a journal than when they appear in a book.