當我讀書的時候，我睡著了。

While I was reading, I fell asleep.

Source: Tatoeba

Sentence Composition

=1 當 dāng
  1. to be
  2. to act as
  3. manage
  4. withstand
  5. when
  6. during
  7. ought
  8. should
  9. match equally
  10. equal
  11. same
  12. obstruct
  13. just at (a time or place)
  14. on the spot
  15. right
  16. just at
=1 當 dàng
  1. at or in the very same...
  2. suitable
  3. adequate
  4. fitting
  5. proper
  6. to replace
  7. to regard as
  8. to think
  9. to pawn
  10. (coll.) to fail (a student)
2 我 wǒ
  1. I
  2. me
  3. my
3 讀書 dúshū
  1. to read a book
  2. to study
  3. to attend school
=4 的 de
  1. of; ~'s (possessive particle)
  2. (used after an attribute when it modifies a noun)
  3. (used at the end of a declarative sentence for emphasis)
  4. (used after a noun, verb or adjective to form a nominal expression, as in 皮革的 pígéde "one made of leather" or 跑堂儿的 pǎotángrde "a waiter (literally, one who runs back and forth in a restaurant)" or 新的 xīnde "new one")
  5. also pr. dì or di in poetry and songs
=4 的 dī a taxi; a cab (abbr. for 的士 dīshì)
=4 的 dí really and truly
=4 的 dì (bound form) bull's-eye; target
5 時候 shíhou
  1. time
  2. length of time
  3. moment
  4. period
6 我 wǒ
  1. I
  2. me
  3. my
7 睡著 shuìzháo to fall asleep
=8 了 le
  1. (completed action marker)
  2. (modal particle indicating change of state, situation now)
  3. (modal particle intensifying preceding clause)
=8 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)
=8 了 liǎo
  1. (of eyes) bright
  2. clear-sighted
  3. to understand clearly
=8 了 liào unofficial variant of 瞭 liào