なかなか〜ない details

just won't + write + not

nakanaka kakanai

just won't; not easily — what was expected keeps failing to arrive, though the conditions for it are all there

meaning: just won't write

話はなしが長ながくて、会議かいぎがなかなか終わらおわらない。

hanashi ga nagakute, kaigi ga nakanaka owaranai.

People keep talking, and the meeting just won't end. neutral

引ひっ越こしてから半年はんとしたつのに、なかなか慣なれないんだよね。

hikkoshite kara hantoshi tatsu noni, nakanaka narenai n da yo ne.

It's been six months since I moved, and I still just can't settle in. casual

Examples

just won't happen; not easily — the awaited event keeps failing to come about, however long one waits or tries

話はなしが長ながくて、会議かいぎがなかなか終おわらない。

hanashi ga nagakute, kaigi ga nakanaka owaranai.

People keep talking, and the meeting just won't end. neutral

引ひっ越こしてから半年はんとしたつのに、なかなか慣なれないんだよね。

hikkoshite kara hantoshi tatsu noni, nakanaka narenai n da yo ne.

It's been six months since I moved, and I still just can't settle in. casual

部品ぶひんが不足ふそくしており、修理しゅうりがなかなか進すすんでおりません。

buhin ga fusoku shite ori, shuuri ga nakanaka susunde orimasen.

Parts are in short supply, and the repairs are making very slow progress. formal

中々 — the kanji spelling, mostly in older print; kana is the modern norm in both writing and speech.

Without a negative なかなか praises instead — なかなかおいしい means "rather
good", not "hardly tasty".

めったに〜ない
めったに counts occasions and says they almost never come round (めったに飲のまない — the drink is simply not part of this life); なかなか says the occasion is wanted and keeps not arriving, so it carries the speaker's impatience and is odd about anything nobody is waiting for.
まだ
まだ来こない reports the plain fact that the arrival has not happened yet; なかなか来こない adds that it is taking longer than it should, which is why なかなか sits so naturally in a complaint and まだ in a status report.
（よ）うとしない
ようとしない blames the person — they will not even try (子こどもが野菜やさいを食たべようとしない); なかなか〜ない blames nobody and only measures the delay, so it stays usable about weather, buses and machinery.