I have been busy yesterday afternoon为什么要用have been busy而不用ha

I have been busy yesterday afternoon为什么要用have been busy而不用ha I have been busy since yesterday. I have been very busy. have been busy”与“I'm very busy”的区别 -You have been quite busy the whole afternoon. I have been sick since yesterday.中have been 是什么是时态为什么要用been. what i have been busy with recently is___the college entranc I have been very busy training for my next competition I have been very busy the last few days I have been busy since yesterday.现在完成时是have加过去分词,但这里的过去分词在哪里 wow,you have been so busy we both have been very busy