表示从过去的过去开始，持续到过去的动作或情况，期间一直有规律的在进行、不曾间断，并且有可能会继续延续下去。此时经常用延续性动词。

例：The old clock had been being taken apart of and fixed up again for several times by my 10-year old son before I came back home.

我回到家之前，我10岁大的儿子已经把这个旧钟表拆卸并重新组装了好几回了。

强调在过去将来的某个具体时间正在发生的动作或存在的状态。 

例：The government promised that a new highway would be being built next July.

政府承诺说第二年7月将有一条新的高速公路正在修建。

表示到过去将来某一时间已经完成的动作，并且对过去将来那一时间点产生影响。（过去时间点上发生的将来完成时）

例：I believed by the end of that year an advanced version of that software would have been developed, but I was wrong.

我坚信到那年年底为止，那个软件的新版本将被开发出来。但是我错了。

表示动作从过去某一时间开始一直延续到过去将来某一时间，并且有可能继续延续下去。

例：He told me that by the end of the year he would have lived there for thirty years.

他告诉我，到那年年底为止他将已经在那里住了三十年了。

表示动作从过去某一时间开始一直延续到过去将来某一时间，期间一直有规律在进行、不曾间断，并且有可能继续延续下去。

例：They said that by the end of the following month, the project would have been being worked for 3 years.

他们说到第二个月底为止，这项工程就已经不停地进行了3年了。