我离开家已经一年了。我离家已经一年了。自从我到家以来，我一直在做作业。
have/has + been +since表示过去并持续到现在,那么不加since,只是have been 是不是意思一样呢?I have received from my brother 跟 I have been received from my brother。 I have already typed it 与 I have been typed it .有什么区别?the patient had been dead / the patient had dead / the pat...
have been……since……讲解 1、翻译：已经……自从……，表示从过去到现在一只持续某状态 2、用法：been+n/doing+since+过去时 过去时需是一个时间点，不能是一个表示一段时间的名词！
应该是二者的词性不同吧：have since been 中的since是副词，修饰have been。但是have been since中的since是个连词，它后面必须要接点什么东西。eg：the building has since been under constuction .the building has been under construction since 2009.(接了时间点）...
ADV When you are talking about an event or situation in the past, you use since to indicate that another event happened at some point later in time. 此后; 后来• About six thousand people were arrested, several hundred of whom have since been released. 约六千人被逮捕,不过他们中有几百人...
have done for/since和have been doing for/since 完成时，表示动作结束了|||完成进行时，动作还在继续。i have lived in U.S. for 2 months 我已经住在美国2个月,说话时为止有两个月。i have been living in U.S. for 2 months 2个月来我一直生活在美国——并将继续下去一段时间。i ha...
这里没有错误，have been 的确是表示过去完成时，但是这个句子中加了since,句意就改变了，since表示自从的意思。
have been的本质，是be动词的完成式，传统语法解释为：be动词的“现在完成时”语法结构，与中文意义近似...
"We have known each other since we were at college." 这句话说明说话者和对方自从上大学时就相识了，但并不意味着说话者还在上大学。这里的 "have known" 是 "know" 的现在完成体形式。因此，"have been" 并非总是表示一个状态的结束。它代表一个动作或状态的开始，这个动作或状态可能已经结束...
如果要表示说话时“我们”还在大学念书，那就得用现在完全体： ... since we have been at college...