semiinfinitives

Semiinfinite forms, or semiinfinitives, are a class of non-finite verb forms described in some grammars as lying between the infinitive and the participle. They occur in non-finite clauses and typically do not bear finite tense or subject agreement, though they may carry limited marking for aspect, mood, or evidentiality. Because the term is not universally used and definitions vary by theory, semiinfinitives are best understood as a family of related but language-specific forms rather than a single universal category.

Formation and distribution vary across languages. In some systems, the semiinfinitive is derived from an infinitive stem by a participial or modal suffix; in others, it arises from specialized periphrastic constructions that combine an auxiliary with a non-finite stem. Semiinfinite clauses commonly appear in complement positions after verbs of perception, desire, control, or a similar semantic domain, as well as in certain purposive or prospective constructions. They may also function in noun-like or adverbial roles within larger sentences.

Functions and properties. The primary role of semiinfinitives is to provide a non-finite clause with a nuance that differs from a bare infinitive or a full participle. They can express aspectual distinctions, hypothetical or prospective readings, and sometimes evidential or modal nuances without creating a finite clause. The exact distribution, morphology, and interpretation of semiinfinitives differ across languages, and some grammars treat closely related forms as infinitives with extra markers rather than as a distinct category.

See also: infinitive, non-finite clause, participle, control.