我不知道他今晚會不會來。

I wonder if he'll come tonight.

I don't know if he can come tonight.

Source: Tatoeba

Sentence Composition

1 我不知道 wǒbùzhīdào I don't know.
2 他 tā
  1. (third-person singular) (since the early 20th century, usu. male) he; him; his
  2. (bound form) other; another; some other (as in 他日 tārì and 他人 tārén)
3 今晚 jīnwǎn tonight
4 會不會 huìbùhuì
  1. (posing a question: whether sb, something) can or cannot?
  2. is able to or not
5 來 lái
  1. to come
  2. (used as a substitute for a more specific verb)
  3. hither (directional complement for motion toward the speaker, as in 回来 huílai)
  4. ever since (as in 自古以来 zìgǔyǐlái)
  5. for the past (amount of time)
  6. (prefix) the coming ...; the next ... (as in 来世 láishì)
  7. (between two verbs) in order to
  8. (after a round number) approximately
  9. (used after 得 dé to indicate possibility, as in 谈得来 tándelái, or after 不 bù to indicate impossibility, as in 吃不来 chībulái)