"A non-combined (or prototypical) converb may be defined (a) positively - as a verb form semantically related to another verb form, and (b) negatively - as a verb form which does not occur in the position (1) of the predicate of a simple non-elliptical sentence, (2) of the attribute to a noun, (3) of the complement in complement (object) clauses, (4) of the subject. In the above mentioned four positions the following verb forms occur: (1) a finite form, (2) a participle, (3) an infinitive, (4) a gerund.