我不知道天色變暗了。

It became dark before I knew it.

Source: Tatoeba

Sentence Composition

1 我不知道 wǒbùzhīdào I don't know.
2 天色 tiānsè
  1. color of the sky
  2. time of day, as indicated by the color of the sky
  3. weather
3 變暗 biànàn to darken
=4 了 le
  1. (completed action marker)
  2. (modal particle indicating change of state, situation now)
  3. (modal particle intensifying preceding clause)
=4 了 liǎo
  1. to finish
  2. (used with 得 dé or 不 bù after a verb to express (im)possibility, as in 忘不了 wàngbuliǎo "cannot forget")
  3. (literary) (usually followed by a negative such as 无 wú or 不 bù) completely (not); entirely (not); (not) in the least
  4. to understand clearly (variant of 了 liǎo)
=4 了 liǎo
  1. (of eyes) bright
  2. clear-sighted
  3. to understand clearly
=4 了 liào unofficial variant of 瞭 liào