なかなか

なかなか is a versatile modifier that emphasizes that something is hard to achieve, take longer than expected, or is notable in degree. In negative clauses, it strongly conveys that something is difficult or slow to happen, often with an implication of persistence or effort. In affirmative or descriptive use, it can mean “quite” or “considerably” to express a positive, noticeable degree, especially with adjectives or verbs that convey evaluation or effort. Typical contexts include tasks that are slow or challenging, or praising something that is better than expected.