výkonnou

"Výkonnou" is the instrumental singular feminine form of the Czech adjective "výkonný". The adjective "výkonný" translates to "powerful," "efficient," "effective," or "high-performing" in English. When used in the instrumental case, it modifies a feminine noun that is serving as the means or instrument by which an action is performed.

For example, in a sentence like "Pracovala výkonnou metodou" (She worked with an effective method), "výkonnou" is the instrumental feminine form of "výkonný" and describes the "metodou" (method). It signifies that the method was powerful or efficient, contributing to her successful work.

The instrumental case in Czech is often used to express how something is done, with what, or by what means. Therefore, "výkonnou" indicates a feminine noun's powerful or efficient nature as it relates to an action. It's a grammatical form specific to the feminine gender and the instrumental case in the Czech language. Understanding its context is key to correctly interpreting its meaning in a sentence.