tapahtumisiin
Tapahtumisiin is a Finnish noun-form derived from tapahtuma, meaning “event.” It appears as a plural inflection with the suffix -isiin and has historically been used in some dialects and older texts to convey ideas related to movement toward or into a group of events. In contemporary standard Finnish, the usual illative plural form for “to events” is tapahtumiin, so tapahtumisiin is regarded as archaic, dialectal, or literary rather than common in everyday prose.
Etymology and form: The base is tapahtuma with a plural inflectional ending that resembles other Finnish case
Usage and distribution: The form occurs primarily in historical writings, poetry, or regional speech, where older
Comparison with standard forms: For expressing “to events” in modern Finnish, most speakers would use tapahtumiin.
See also: Finnish language, Finnish grammar, illative case, translative case, tapahtuma.