The article discusses functional-grammatical features of the morphology and syntax of the infinitive which is the most obvious verbum infinitum in the Swedish verb paradigm. The suggested interpretation argues that the traditional distinction of Swedish grammars between verbal and nominal functions of the infinitive can be replaced by an opposition of infinitival functions proper and substantive-infinitival functions. The infinitival function proper includes the use of the infinitive in verb chains (mostly as part of the predicate), in adverbial circumlocutions with prepositions, as well as in syntactic constructions with nexus (the object and the subject with the infinitive). In all cases syntactic functions of the infinitive are realised on the sentential level.
The substantive-infinitival functions comprises the use of the infinitive in syntactic positions of the grammatical subject: as the theme (topic) as well as the rheme (comment) in the context of the formal subject det, the predicative (including the sentences of equivalence with the infinitive in both parts of the subject-predicate structure), a prepositional or prepositionless (direct and indirect) object, a postpositional noun attribute (with direct adjunction or with prepositional syntactic connection). Whatever the syntactic position of the substantive word, the analysis at the level of a full sentence reveals functional-grammatical features of the infinitive as a non-predicate verb form.
Unlike the parts of sentence expressed by nominal parts of speech, the infinitive with a preposition and without a preposition, depending on the type of syntactic connection, which is determined by the valency either of the governing verb or of the substantive word modified by it, is drawn into the verb chain, demonstrating at the same time the features of the morphology and syntax of the verbum infinitum.
The special functional-grammatical features of the Swedish infinitive are determined by the typological features of the grammatical system of the language in the verb paradigm (the expression of grammatical semantics with agglutinative markers and analytical forms and constructions) as well as in verb syntagmas (the expression of syntactic connection between words by use of adjunction or prepositional connection).