The word "勉为其难" is formed through a sequential combination of characters where "勉" (strive) functions as the main verb urging action, "为" (do) serves as the preposition or auxiliary verb indicating the action to be taken, "其" (that) acts as a demonstrative pronoun specifying the target, and "难" (difficulty) serves as the nominal object representing the challenging task. This structure creates a literal meaning of "strive to do that difficult thing", which idiomatically conveys the sense of reluctantly undertaking something arduous.