Tehtäväin

Tehtäväin is a Finnish instrumental case form derived from the noun tehtävä, which means “task” or “assignment.” As an adverb, tehtäväin literally translates to “by means of a task” or “in the course of a task,” and it is used to indicate that an action occurs while a task is being performed or that a particular method involves carrying out a task. The form is technically the same as the instrumental case ending –in, used to express means or instrumentality.

The word appears primarily in written Finnish, especially in academic and technical contexts where processes are described in terms of tasks or duties. It is less common in everyday speech; speakers usually prefer phrases such as tehtävän aikana (while doing a task) or tehtävän aikana. In literary usage, tehtäväin can give a concise, formal tone, akin to the English adverbial “in the performance of.” Examples include sentences such as “Projektin ohjaaja valvoi etenemistä tehtäväin” (The project manager monitors progress while performing tasks).

Though not a common modern term, tehtäväin is grammatically valid and can be found in dictionaries of Finnish morphology. It illustrates how Finnish uses case endings to form adverbial phrases that convey the method or means of an action.