Infinitives and their relatives: Defining infinitives in ancient Indo-European languages

Infinitives are traditionally classified as verbal forms, but they evolve from nouns (Haspelmath 1989); they usually show features of adverbial morphology (lack of inflection), but syntactically share properties with both nouns and verbs. By challenging our understanding of fundamental linguistic categories, infinitives prove particularly difficult to define.

My thesis will ask what being an infinitive really means in the Indo-European languages: what characteristics are essential to the definition of infinitives across these languages, and which of them reflect syntactic processes that are language-specific? To answer these questions, I will study infinitives in relation to the development of the grammatical categories of tense, aspect, modality and evidentiality (TAME), using the methods and insights of historical-comparative and theoretical linguistics alike.

While hitherto untried in previous Indo-Europeanist scholarship on the matter, such an integrated approach promises to be beneficial to both disciplines.

Infinitives manifest different properties cross-linguistically, and what applies to infinitives in Indo-European languages does not necessarily apply to infinitives in other languages. Nonetheless, studying Indo-European infinitives can offer insights that are relevant beyond Indo-Europeanist scholarship, and contribute to the larger theoretical question of what non-finite verb forms truly are.

By studying the interactions between TAME categories and ancient Indo-European infinitives, I aim to shed light on how infinitives develop. Can we establish tendencies in the ways that infinitives progressively integrate TAME categories in Indo-European languages? Is there a typical order in the way in which infinitives acquire verbal characteristics?