"I know." and "I don't know." in Japanese

I know. I don't know.
  • I know. (polite)   しっています。Shitte imasu.
  • I know. (casual) しって(い)る。Shitte(i)ru.
  • I don't know. (polite) しりません。Shirimasen. (X しっていません。Shitteimasen.)
  • I don't know. (casual) しらない。Shiranai. (X しってない。Shittenai.)

X = no good, incorrect, wrong