中々
なかなか · nakanaka · JLPT N4 · adverb
very
中 = middle, doubled: well past the middle, so quite / considerably
々 is the repeat mark, so 中々 is naka + naka. One naka is only the middle; saying it twice pushes past halfway into quite a lot. With a negative verb it flips to not easily: nakanaka konai = it just won't come.
中 — vertical stroke 丨 through enclosure 口
Pictograph of a banner or pole piercing the center of a target or territory, depicting the idea of 'middle' or 'center'. The horizontal frame represents boundaries, and the vertical line marks the central axis. The meaning extended from spatial center to 'middle, central, China' (中国, the Middle Kingdom).