英文 名詞和動詞的問題

為什麼依據英文句子可以用動詞或名詞來變化?
例子:
1 disappointment (n):Much to my disappointment ,She refuse my invitation.

2disappint(v):I was disappointed at the result of election.
請問各位大大像第一句disappointment為什麼不能換成disappoi...
3 answers 3