我不知道該怎麼形容。

I can't really describe it.

Source: Tatoeba

Sentence Composition

1 我不知道 wǒbùzhīdào I don't know.
2 該 gāi
  1. should
  2. ought to
  3. probably
  4. must be
  5. to deserve
  6. to owe
  7. to be sb's turn to do sth
  8. that
  9. the above-mentioned
3 怎麼 zěnme
  1. how?
  2. what?
  3. why?
4 形容 xíngróng
  1. to describe
  2. (literary) countenance; appearance