YOU SAID:

I'm a random person that no one knows about that can speak English.

INTO JAPANESE

私は英語が話せることを誰も知らないランダムな人です。

BACK INTO ENGLISH

I'm a random person who doesn't know that I can speak English.

INTO JAPANESE

私は英語が話せることを知らないランダムな人です。

BACK INTO ENGLISH

I'm a random person who doesn't know to speak English.

INTO JAPANESE

私は英語を話すことを知らないランダムな人です。

BACK INTO ENGLISH

I'm a random person who doesn't know to speak English.