你睡覺之前不要忘了熄燈。

Don't forget to put out the light before you go to bed.

Source: Tatoeba

Sentence Composition

=1 你 nǐ you (informal, as opposed to courteous 您 nín)
=1 你 nǐ you (Note: In Taiwan, 妳 is used to address females, but in mainland China, it is not commonly used. Instead, 你 is used to address both males and females.)
=2 睡覺 shuìjiào
  1. to go to bed
  2. to sleep
=2 睡覺 shuìjué
  1. (archaic, intransitive) to wake up
  2. to wake up
3 之前 zhīqián
  1. before
  2. prior to
  3. ago
  4. previously
  5. beforehand
4 不要 bùyào don't!; must not
5 忘 wàng
  1. to forget
  2. to overlook
  3. to neglect
=6 了 le
  1. (completed action marker)
  2. (modal particle indicating change of state, situation now)
  3. (modal particle intensifying preceding clause)
=6 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 無 wú or 不 bù) completely (not); entirely (not); (not) in the least
  4. to understand clearly (variant of 瞭 liǎo)
=6 了 liǎo
  1. (of eyes) bright
  2. clear-sighted
  3. to understand clearly
=6 了 liào unofficial variant of 瞭 liào
7 熄燈 xīdēng
  1. turn out the lights
  2. lights out