As a replacement for the obligatory negative statements in standard Japanese (
ないといけない,
なければいけない, なくてはだめ, etc),
なあかん may be used in 関西弁（かんさいべん）. あかん itself is a 関西弁（かんさいべん） word that means ‘useless’, or ‘no good’, and is utilized almost as a direct replacement for だめ.
な will pair with the standard negative form of any verb, before adding あかん straight after it. な itself in this structure is an abbreviation of the 助動詞（じょどうし） (auxiliary verb) ない, in which い has been omitted. なあかん can be translated as ‘must do (A)’, but more literally is ‘not doing (A) is no good’.
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野菜（やさい）もちゃんと食（た）べなあかんで。
You have to eat your vegetables too.
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そういえば今日（きょう）は祖母（ばあ）ちゃんの家（いえ）に行（い）かなあかんかったやん。
By the way, I had to go to my grandma's house today.
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あんたももう中学生（ちゅうがくせい）なんやから、家事（かじ）の手伝（てつだ）いせなあかんよ。
Because you are already in middle school, you have to help out with chores.
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来週（らいしゅう）行（い）くキャンプ場（じょう）の周（まわ）りにはコンビニとかあらへんから、自分（じぶん）たちで食（た）べ物（もの）とか持（も）ってこなあかんで。
There is nothing like convenience stores around the campsite we are going to next week, so you'll have to bring things such as food on your own.
As with many other grammar points,
する will appear slightly differently in 関西弁（かんさいべん） when partnered with
なあかん. The most common form that
する will be seen in is
せなあかん. せ is the negative base of
する in Kansai dialect, followed by な (rather than the customary へん).
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まだまだ練習（れんしゅう）せなあかんな。
I still have to keep practicing.
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子供（こども）がああいう事（こと）したらちゃんと注意（ちゅうい）せなあかんで
。
When your kid does something like that, you have to warn them about it.
More correctly, な is an abbreviation of なければ, the 仮定形（かていけい） (hypothetical form) of ない that has been paired with the 接続助詞（せつぞくじょし） (conjunction particle) ば. However, in standard speech, なあかん can realistically replace any obligatory negative structure, not just なければ.