1、would have been通常用在虚拟语态中，表示将会做与过去事实相反的动作。
2、would have been就属于would have done的句式，其中been是be的过去分词。
拓展资料
would have been
1、It would have been virtually impossible to research all the information.
要对所有的信息进行分析研究几乎是不可能的。
2、What I did was right and if I had done anything less it would have been wrong
我做的一切都是正确的，如果我少做了一点点，就会出错。
3、It would have been rough justice had he been deprived of this important third European win.
要是他被剥夺了这一意义重大的第三个欧洲冠军头衔，那对他简直是太不公平了。
4、My daughter would have been 17 this week if she had lived
我女儿要是还活着的话，这周就17岁了。
5、He made a promise to his great-grandfather? That would have been a long time ago
他曾向他的曾祖父许下承诺？那准是很久以前的事情了。
6、I would have been much wiser to start my own pension plan when I was younger.
我要是年轻点时就开始自己的养老金计划就明智多了。
7、I don't believe for one minute she would have been scared
我压根不认为她会有所畏惧。
8、Before we had our child the idea of staying in every night would have been horrific.
在有孩子前，我们认为每天晚上呆在家里的想法是很可怕的。