semiinfinitive

Semiinfinite is a term used in some linguistic grammars to describe a non-finite verb form that lies between the infinitive and the finite verb. It is not a universal category, and its exact definition and distribution vary across languages and scholarly traditions.

In descriptions that employ the term, semiinfinitives are typically non-tensed and lack subject agreement; they may be derived from the infinitive by specific morpho-syntactic processes or by the addition of particular particles or affixes. They usually do not carry full finiteness, yet they can participate in clausal structures that resemble those of infinitives, such as complement clauses, purpose clauses, or adjuncts to other verbs.

The functional profile of semiinfinitives differs across languages. In some descriptions they behave like infinitives in taking non-finite complements, while in others they combine infinitive-like semantics with participle-like syntax.

Because the category is not universally recognized, many grammars instead classify such forms under standard non-finite categories (for example infinitives, bare infinitives, present participles, or past participles) depending on their specific properties.

Semiinfinite forms are most often discussed in theoretical or historical grammars, where researchers aim to capture intermediate forms that do not fit neatly into canonical non-finite classes. The term therefore serves as a descriptive label rather than a universally defined morphosyntactic category.