have been done 与 having been done 与have been doing与having been doing有什么区别

have been done
已被做完
having been done
是上面的现在分词短语.
have been doing
在过去动作开始一直在进行着.
having been doing
是上面的现在分词短语.
明了吧.

如果作业是主语，

作业已经被做完 have been done

从一小时前到现在我一直在做这个作业 have been doing

having been done，having been doing 分别表达上述的意思，只不过整个短语被用作名词做主语或宾语

前者是做过的事，结束有一定时间。后者是在被做，强调距离现在时间短