Is こたぁねえ= ことはない? [duplicate]

Question

Context: a group of men are walking down a secluded road, they get the feeling they're being followed and sure enough their hunch is proved right when they're suddenly attacked, a projectile is launched at them but they manage to dodge it (at this point their attacker is still hidden).

One of the men tries to provoke this hidden assailant to draw them out by calling their attack weak and sluggish, he also says this:

まさかと思うが、今のが必殺技ってこたぁねえよな？

What I'm not sure about is "こたぁねえ" is this a contraction of "ことはない" in which case the speaker would be saying:

Whether or not you believe it, it's not like that was a lethal technique just now was it?

Or if this is totally the wrong assumption, what is the correct way to parse that sentence?

Answer 1

First, I would mention the meaning behind the expression 「まさかと思う」would be best represented as follows:

「まさかと思うが、」 ‘It seems impossible, but’　or ‘By any chance, was that...’

‘Believe it or not,’ would be closer to 「まさかと思うだろうが、」

Full translation:

That couldn’t possibly have been a lethal technique.

As has been commented, you can find more information about 「こたぁねぇ」on previous posts. This speech tendency is mostly used by ‘tough’ types (typically men), or used by regular people to sound rough (either seriously or as a joke) or to demonstrate frustration and indignation, ex. 知らねぇよ！ It might just be easier to think of it as regional slang.

Many of these formed from regional dialects. This example of morphing the language seems to be referred to as 促音便化 or 音便. I believe that your example is more representative of 下町言葉 (江戸弁）, specific to the central Tokyo area. In Kansai, for example, こっちゃ is used quite a bit, as in 「えらいこっちゃでえ」, meaning ‘It’s serious’ or ‘Oh crap!’ (大変なこと）. This is referred to as 音変化 here . You can also find some examples of 下町言葉 here.