Confusing on understanding【知ってるであるか】


why there is a verb 「知ってる」plus another[であるか]？ [![enter image description
here](https://i.stack.imgur.com/hJTYg.jpg)](https://i.stack.imgur.com/hJTYg.jpg)




It's 100% ungrammatical in standard Japanese, but some fictional characters
speak like this. This is a [キャラ語尾](https://dic.pixiv.net/a/%E8%AA%9E%E5%B0%BE)
that is sometimes referred to as である口調. A typical user of this 語尾 is an
eccentric doctor or a dumb and pompous aristocrat, and they often use 吾輩 as a
first-person pronoun. In addition to standard usages like 本当である, users of
である口調 may speak like this:

  * そうであるか (←そうですか)
  * おいしいである (←おいしいです)
  * 見たである (←見たよ)
  * 行くである (←行きましょう・行きなさい)
  * おはようである (←おはようございます)

There is also なのだ/なのです口調 (see
[this](https://japanese.stackexchange.com/a/85831/5010)).

