present perfect continuous: has ('s) / have ('ve) + been + ing present perfect simple: has ('s) / have ('ve) + past participle If the contracted forms present the greatest difficulty, it will be ...

I have been singing all day. She has been reading. Some people have been in government since 1999. The lecturer has been teaching at UNILAG for eight years. He has been sleeping in the other room.

Here the simple past is used: 'I went to the cinema three times last week.') If you use since with the present perfect or present perfect continuous, you are signalling when something started.