1.
quite, rather, fairly (with affirmative)
To a considerable degree.
なかなかいい。
It's quite good.
2.
not easily, hardly (with negative)
Indicating difficulty or taking a long time.
なかなか changes meaning depending on whether the sentence is affirmative or negative.
WITH AFFIRMATIVES (quite, rather):
Expresses moderate praise or acknowledgment.
WITH NEGATIVES (not easily, hardly):
Expresses difficulty or that something takes time.
Usage
In positive contexts, なかなか suggests "better than expected" or "surprisingly good." In negative contexts, it conveys mild frustration or resignation about difficulty.
Related Words
Compare:
かなり (fairly, quite, considerably)
Compare:
大分 (considerably, fairly, quite)
Compare:
だいぶん (considerably)