The phrase "taken for granted" originates from the 17th-century legal and financial sense of "grant," meaning to bestow or allow. The core logic of the phrase lies in the verb "take," which here means to accept or assume. The construction implies something is accepted ("taken") as if it had been formally given or assured ("granted"), without requiring proof or acknowledgment. Over time, it evolved from describing concrete agreements to describing an unthinking psychological acceptance, where the benefits or existence of something are assumed to be permanent and unremarkable. This semantic shift reflects a move from a transactional, legal framework to a more abstract, social-psychological one, capturing the human tendency to undervalue what is consistently present.

This is a fixed adjectival phrase composed of the past participle of the verb "take", the preposition "for", and the past participle of the verb "grant". It functions as a single lexical unit.