[xigoi]

Also French: je ne sais (I don’t know) → je ne sais pas (I don’t know a step)

[Jakob]

And recently even dropping the negation itself while keeping the meaning: “je sais pas”

I never thought about that. Interesting. This negation related cycle is apparently called Jespersen’s cycle and happens in many languages. The English equivalent

I say not -> I “do” not say -> I don’t say. -> ?

https://en.wikipedia.org/wiki/Jespersen%27s_cycle