The Chinese idiom 插翅难飞 is formed by sequentially combining the characters 插 (insert), 翅 (wings), 难 (difficult), and 飞 (fly), creating a literal meaning of "even if wings are inserted, it is difficult to fly". This structure establishes a hypothetical condition where adding wings does not enable flight, thereby conveying the idea of inescapability through a direct, metaphorical relationship between the characters.