I have been telling you that I think you are making a great mistake .I think 是插入语吗?这句话如何翻译

英语句子结构分析的问题,I reckon William could have been telling the truth.could have been telling 请问这是什么时态?是虚拟语气吗?如果是虚拟语气,为什么不用could have told the truth? I have been telling you that I think you are making a great mistake .I think 是插入语吗?这句话如何翻译 I have been selling I have been trying I have ever been I too have been I have been to. I have been I have been in. —— many times,I still could not understand how to operate the machine.A：Having been told B：having told C：I have been told D：telling 为什么不选c I have been there,have been 是have been in还是have been to的缩写? i have always been there i have never been there I HAVE NEVER BEEN,能否说I never have been I have been so serious I have been so serious I-have-been-at-home I have always been you I have been loving you I have been a person .