终于

     The adverb “ 终于” is used as an adverbial, indicating that an expected result has finally been attained.
终于+V
  饭终于做好了。
  他们终于爬上了万里长城。
  他研究了很长时间，这个问题终于解决了。
The word following “终于” must consist of two or more syllables.

终于+A
  她的病终于好了。
  书架上的书终于整齐了。 
   Adjective applicable in this construction are limited to the ones indicating a change in the state.