jäsenseen
Jäsenseen is a form occasionally encountered in discussions of Finnish grammar as a nonstandard or archaic illative form of the noun jäsen, which means member. It is not used in contemporary standard Finnish, where the illative singular is usually jäseneseen. The appearance of jäsenseen is typically described in linguistic notes as a dialectal or historical variant, rather than as a characteristic of modern written Finnish.
In linguistic terms, jäsenseen would be analyzed as an illative form derived from the stem jäsen with
Usage and guidance: In teaching, editing, and formal writing, prefer jäseneseen when expressing the illative “to/into
See also: Finnish language, Finnish grammar, Illative case, Jäsen.