act as 与act for的用法

　　1 . act as 担任，充当，起的作用。如：

　　A trained dog can act as a guide to a blind person. 经过训练的狗可以担任盲人的向导。

　　表示担任独一无二的职务，其前通常不用冠词。如：

　　He acted as manager in my absence. 我不在时他担任经理。

　　I dont understand their language; youll have to act as

　　interpreter. 我不懂他们的语言，你得当翻译了。

　　2 . act for 代理，代为。如：

　　Please act for me during my absence. 我不在时请代理我处理事务。

　　I acted for our captain while he was in hospital. 我们队长住院时由我代理他。