過去將來完成進行時VS現在和將來完成進行時
同爲完成進行時，過去將來完成進行時、現在完成進行時和將來完成進行時非常相似。不過歸根結底，只要弄清楚了時間點，就很好分辨了。
過去將來完成進行時
表示動作從過去某時間開始一直延續到對於過去來說的將來的某一個時間。
基本形式：should/would + have + been + doing
現在完成進行時
基本形式：have/has + been + doing
表示過去某時間點開始的動作或狀況一直持續到現在（可能繼續或就此停止）
將來完成進行時
基本形式：shall/will + have + been + doing
表示某種狀況一直持續到說話人所提及的時間。
例句對比：
（1）傑克工作。
Jack said that he would have been working hard by the end of the year.
Jack has been working hard.
Jack will have been working hard by the end of the year.
（2）演出持續了3個月。
By then the play would have been running for three months.
The play has been running for three months.
By then the play will have been running for three months.
（3）她將受到治療。
The doctor said that she would have been having treatment all her life.
She has been having treatment all day.
She will have been having treatment all her life.
（4）他生活在這裏有10年了。
By the end of the month he would have been living here for ten years.
He has been living here for ten years.
By the end of the month he will have been living here for ten years.
（5）傑克會感覺很棒。
Her mother said that Jack would have been feeling very well.
Jack has been feeling very well recently.
Jack will have been feeling well.
從例子我們可以看出三者的主要區別爲過去對未來的看法、現在的狀態和未來的事情。
