The topic of this dissertation is the formation of aspectual pairs of modern loan verbs in Russian. The questions it aims to answer are which aspectual affixes (prefixes and/or suffixes) are used to form aspectual pairs and what are the reasons behind the choice of aspectual affix?

The dissertation consists of four articles and an introductory section (“summary”). The summary discusses theoretical issues regarding verbal aspect, aspectual pairs, and loan verbs, as well as the results of the four articles and my interpretation of the results.

Article I is an observational study of verbs borrowed into Russian during the 20th century and their aspectual pairs in nine dictionaries aimed at a general audience. The most common perfectivizing prefix in this study is za-, with 17 verbs. In second place is s-, in third place pro-, and the fourth most common prefix is ot-. After these prefixes, the prefix po- is attested for two verbs, and attested with one single verbare na-, o-, and raz-.

Article II reports on an experiment in which 120 native Russian speakers were asked to form perfective counterparts of a number of loan verbs, most of which are related to new technologies from the late 20th and early 21st centuries. The participants read constructions with a light verb (or “compensator verb”) and a noun or company name written in italics, and were asked to form a synonymous verb in the same aspect as the light verb. An example is postavit´ lajk ‘press “like” [=the “like” button on social media sites or apps]’, to which most respondents answered lajknut´ ‘like’. The most common perfectivizing affixes for the 19 perfective verbs in the experiment turned out to be -nu- and za-, followed by pro-, ot-, and s-. The results of this study furthermore indicate that prefix variation is common in recent loan verbs in Russian, as no verb in the study showed 100% agreement by all participants in the choice of aspectual affix.

The two last articles discuss prefix variation in loan verbs, i.e. imperfective verbs with two or more corresponding perfective verbs. Article III is a case study of the verb guglit´ ‘google’ and semantic differences between its corresponding perfectives zaguglit´, naguglit´, poguglit´, and proguglit´ on the basis of the co-occurrences (adverbs and direct objects) in Russian mass-media texts collected from the Integrum mass-media database. Article IV is written in Russian and is concerned with prefix variation in a broader sense: stylistic, diachronic, and semantic facets of prefix variation, including prefix variation in loan verbs. It also contains two small corpus analyses. The first shows that some prefixed loan verbs have become outdated, which indicates that prefix variation can also be a diachronic phenomenon. The other is a small co-occurrence study, similar to that in in Article III, on the verbs zašerit´, pošerit´, and rasšerit´, aspectual correlates to šerit´ ‘share (often: on social media, on the internet)’, which show smaller semantic differences than the verbs in Article III za-/na-/po-/proguglit´ ‘google’.

A hypothesis that has guided the work in this dissertation and in all articles is that prefixes in aspectual pairs are not purely aspectual, “empty” markers of perfective aspect, but rather express a specific semantic element also present in the base verb. This hypothesis, called the “overlap hypothesis”, is especially visible in verbs with a spatial meaning and in verbs with prefix variation, where different prefixes underline different semantic nuances of the base verb. A few prefixes (za-, s-, pro- and ot-, as well as the suffix -nu-) have broad meanings and are used in a number of different verbs with different meanings, whereas other, “small” prefixes are used in fewer verbs, with more specific, often spatial, meaning.