käyttääessaan

Käyttääessään is a Finnish grammatical form. It is the translative case of the third infinitive of the verb "käyttää", which means "to use". The translative case in Finnish often translates to "while" or "upon" in English. Therefore, "käyttääessään" literally means "while using it" or "upon using it", where "it" refers to something previously mentioned or understood from context.

This form is used to express an action that is happening concurrently with another action, or an action that is a direct consequence of another action. For example, in the sentence "Hän oli onnellinen käyttääessään uutta autoaan" (He was happy while using his new car), "käyttääessään" indicates the ongoing state of using the car during which he felt happy. Similarly, "Tieto avautui hänelle käyttääessään vanhaa karttaa" (The knowledge opened up to him upon using the old map) shows that the act of using the map led to the revelation of information. The possessive suffix "-än" indicates that the subject performing the action of using is the same as the subject of the main clause.