為何是exempt而不是exempted？文法

exempt adj, if she is exempt from something,she is not affected by it,does not have to do it,eg:-as service as a juror.eg:-female students are exempt from certain exams.
exempt verb, formally to give somebody permission not to do something he would normally have to do:-eg:-His bad health exempted him from juror service...(a passive voice).The charities were exempted from paying the tax.(a passive voice).

2014-07-28 12:38:01 補充：
If exempt used as adj,exempt(adj),then it is not used as exempted (a past participle) as you thought.Hence eg:-Females are exempt from certain exams.

KkY 你好~

其實 exempt 也可被視為形容詞 (adjective)，故此上述句子的 exempt (adj) 其實並非如你所以為的 exempted (動詞作 past participle) 的用法。