nukkuessaan

Nukkuessaan is a Finnish adverbial participle form of the verb nukkua (to sleep). It conveys that an action occurred at the same time as the action described in the main clause, roughly translating to "while he/she was sleeping" or "as he/she slept." The form is typically used to set background circumstances in narrative or descriptive text.

Formation and usage: Nukkuessaan is built from the verb stem nukkua plus the suffix -essaan, which marks a past-time simultaneous action relating to the subject of the main clause. The participle generally agrees with the subject of the sentence (often represented by hän, meaning “he/she”). It is commonly employed in literary and formal prose to add a time frame or ambiance without introducing a separate subordinate clause.

Grammatical notes: The -essaan form belongs to a family of adverbial participles in Finnish that express simultaneity or background action. It is most naturally used when the main clause describes a subsequent or continuing action, and the subordinate idea describes what was happening at the same time. While frequent in written Finnish, it can also appear in formal speech or narration. Other verbs form similar adverbial participles with corresponding roots, such as kävellessään (while he/she was walking).

See also: Finnish participles, adverbial participles, and related forms such as nukkuessa (present-time sleeping) and kävellessään (while walking).