Why use ran in 母さんは 逃げらんなかったんだって

Question

I saw this sentence in an episode of Attack on Titan where a character says

逃げらんなかったんだって

why does the speaker say

逃げらんなかったんだって

instead of

逃げらなかったんだって

what does the ん mean add to the sentence in this context

I know you can say stuff like 知らん to mean 知らない but this is connected to なかった which already makes it negative I don`t understand the use of ん in this context

Answer 1

逃げる is 一段動詞, 知る is 五段動詞. So negating 知る we get 知らない⇒知らん, but that's not what's happening with 逃げる here. That's 逃げられる, the potential or passive form. Since you said this was from 進撃の巨人, I assume it's more likely potential 可能形. The original is probably:

逃げられなかったんだって

As for the change from 逃げられなかった⇒逃げらんなかった, see this canonical answer:

Why is the て-form being used before ん？