The word "着呢" is formed by directly combining the grammatical particle "着", which typically indicates an ongoing state or action, with the sentence-final particle "呢", used for emphasis or to denote a continuing situation. When joined, they function as a single unit suffixed to adjectives to intensify their meaning, emphasizing a high degree or persistent state, as seen in constructions like "好着呢" meaning "very good" or "perfectly fine". This combination draws from the continuous aspect of "着" and the reinforcing role of "呢" to create a fixed expression for amplification.