käsitelleensä
Käsitelleensä is the past active perfect participle of the Finnish verb "käsitellä". The verb "käsitellä" has several meanings, including to handle, to process, to deal with, to treat, or to discuss. Therefore, "käsitelleensä" indicates that someone has completed the action of handling, processing, dealing with, treating, or discussing something, and this fact is being mentioned in relation to another event or state.
This form is often used to express a cause or a preceding action that has a consequence.
Another common usage is in subordinate clauses, often introduced by conjunctions like "kun" (when) or "joka" (who/which).
The structure of "käsitelleensä" involves the past active participle stem of "käsitellä" (käsitelle-) followed by the