elméletnek
elméletnek is the dative singular form of the Hungarian word "elmélet," which translates to "theory" in English. In the Hungarian language, case endings are attached to the end of nouns to indicate their grammatical function within a sentence. The "-nek" ending signifies the dative case, which is often used to express the indirect object of a verb, the possessor, or when something is given "to" someone or something.
Therefore, "elméletnek" would be used in a sentence where a theory is the recipient of an action