我無從得知。

I have no way of knowing that.

Source: Tatoeba

Sentence Composition

1 我 wǒ
  1. I
  2. me
  3. my
2 無從 wúcóng
  1. not to have access
  2. beyond one's authority or capability
  3. sth one has no way of doing
3 得知 dézhī
  1. to find out
  2. to learn of