help pls on "have to" and such

[Chronitsch]

Hi there

I have a problem with a certain form, I am not sure how to pronounce in English

its the folloing

なければなりません
and than this thing with いけません at the end
there also are the versions that are with

なくてはなりません／いけません
なくちゃなりません／いけません
なきゃなりません／いけません

I know its something like "You HAVE to do this and that" or "It is necessary to do", but I do not understand the usage and the difference of the mentioned parts.

Than another thing I stumbled over in a Homework I have to do, I do not know if this comes because of this form, or if there is another reaseon
Following 2 sentences
１時までに　帰んなきゃ　　かえんなくちゃ。
今晩はテストの　勉強やんなくちゃ　　勉強やんなきゃ。

why is there an additional ん　and ... what is this なくちゃ and なきゃ ?

I hope you can help me on this ^^

[toonygal5459]

In very casual conversation or when speaking quickly, ら gets converted to ん.
So where you would ordinarily say 帰らなきゃ it becomes 帰んなきゃ, and やらなくちゃ becomes やんなくちゃ.

なくちゃ and なきゃ are the shortened forms of なくては and なければ

[Chronitsch]

thank you for that, I am not that fluent with very colloquial japanese in that way

now to the　なくては ist it this kanji ->　無くては which mean "unless" ?

this would help to understand this part, but still I am confused in how to build this form and where he differences are :-/

[Jessi]

now to the　なくては ist it this kanji ->　無くては which mean "unless" ?

Technically, yes, the kanji for ない is 無い, but you won't see it used in constructions like this. Just stick to the hiragana

[Chronitsch]

lol i am dummy, should have known that naku comes from nai

I ask my teacher today, luckyly we had a question hour before the test, and she said all those versions can be exchanged freely, just matters if I need to talk polite or casual

at least that is what I understood

am I right with that?