TOEIC®备考：英语未来完成进行时课程
英语中的未来完成进行时用于表达某个动作将在未来特定时刻持续一段时间，并且会一直进行到那个特定时刻。这种时态尤其强调动作的持续性和长度。
如何构成未来完成进行时？
未来完成进行时的基本结构为：will have been + 动词−ing
以下表格总结了英语未来完成进行时的构成方式：
| 形式 | 结构 | 例句 |
|---|---|---|
| 肯定式 | 主语 + will have been + V-ing | I will have been working here for ten years by next January. They will have been studying English for three hours by lunchtime. She will have been living in New York for a decade by 2030. |
| 否定式 | 主语 + will not have been + V-ing（缩写：won't） | I will not have been working here for ten years by 2025. He won’t have been sleeping for very long by the time we arrive. They won’t have been waiting for us because we didn’t tell them we were coming. |
| 疑问式 | Will + 主语 + have been + V-ing ? | Will you have been working here for a year by next month? Will she have been living in Australia for long by the end of the year? Will they have been studying for eight hours straight by this evening? |
| 疑问词开头的疑问句 | 疑问词 + will + 主语 + have been + V-ing ? | How long will you have been waiting by the time we get there? Where will she have been staying during her trip by next summer? |
用未来完成进行时描述在未来某一特定时刻之前已开始并仍在进行的动作
这是未来完成进行时最常见的用法。使用该时态时，强调动作会在未来某一时刻之前已经开始，并且在该时刻仍在持续进行或一直持续到那个时刻。
- By the time he retires, he will have been working in the same company for forty years.
(等他退休时，他已经在同一家公司工作了四十年。) - By 10 p.m. tomorrow, they will have been driving for twelve hours.
(明天晚上十点时，他们已经开车十二小时了。) - By the end of this year, we will have been working on this project for six months.
(到今年年底，我们将已经在这个项目上工作了六个月。)
用未来完成进行时强调动作的持续或进展直到某个时间点
未来完成进行时常用来强调某个动作持续的总时长，直到未来某一时刻。它常回答这样的问题："多久？"或者“已经多久了？”
- In October, I will have been living in this city for five years.
(到十月时，我在这座城市已经住了五年。) - By next summer, we will have been practicing for the marathon for six months.
(到下个夏天，我们已经为马拉松训练了六个月。) - When she arrives, she will have been waiting for her friend for over an hour.
(等她到达时，她已经等朋友超过一个小时了。)
用未来完成进行时比较未来的两个时间点之间的持续
未来完成进行时可以用来比较动作的开始（通常在过去或现在）与未来的状态，强调这两个时间点之间的持续时间。
- By the time you finish your degree, you will have been studying at university for six years.
(等你完成学业时，你已经在大学学习了六年。) - By 3 p.m. tomorrow, I will have been waiting for your call for an hour.
(明天下午三点时，我已经等你的电话等了一小时。) - By the time we leave for vacation, we will have been working non-stop for two months.
(等我们去度假时，我们已经连续工作了两个月。)
未来完成进行时常用的时间标志
有些时间表达常常与 未来完成进行时 搭配使用：
-
By + 具体时刻：By next year, by 2025, by next week, by the time we arrive 等
- By next year, I will have been studying English for five years.
(到明年，我已经学习英语五年了。) - By 2025, she will have been running her business for a decade.
(到2025年，她已经经营自己的企业十年了。)
- By next year, I will have been studying English for five years.
-
For + 时长：For an hour, for three years, for a long time 等
- For a long time, they will have been discussing this topic without reaching any conclusion.
(很长一段时间里，他们一直讨论这个话题但没有得出结论。)
- For a long time, they will have been discussing this topic without reaching any conclusion.
-
By the time + 从句：By the time she leaves, by the time you finish 等
- By the time she leaves, we will have been talking for hours.
(等她离开时，我们已经聊了几个小时。) - By the time the movie starts, we will have been waiting in line for an hour.
(等电影开始时，我们在队伍里已经等了一小时。)
- By the time she leaves, we will have been talking for hours.
-
Next, in, before + 时间点（虽然用得少，但只要有“时长”概念就可以）：
- In six months’ time, I will have been working here for two years.
(再过六个月，我在这里已经工作两年了。) - Before he turns 30, he will have been playing the piano for two decades.
(在他30岁之前，他已经弹钢琴二十年了。) - Next summer, we will have been traveling across Europe for eight weeks.
(下个夏天时，我们已经在欧洲旅行八周了。)
- In six months’ time, I will have been working here for two years.
什么时候不该用未来完成进行时？
虽然未来完成进行时适合表达未来动作的持续时间，但也有不能用的情况：
与静态动词（或状态动词）一起使用时
某些动词描述状态、情感或感知（如 to know, to believe, to own 等）不能用进行时态。此时要用未来完成时（Future Perfect Simple）。
- By next year, I will have known her for a decade.
(正确--“to know”属于状态动词。) - By next year, I will have been knowing her for a decade.
(错误--“to know”不能用于进行时态。)
了解更多内容，请阅读我们的状态动词课程
当强调完成或最终结果时
如果要强调动作完成，而不是其持续过程，应当用未来完成时（Future Perfect Simple）。
- By 5 p.m., I will have finished writing my report.
(下午五点时，我已经写完报告了。) - By 5 p.m., I will have been writing my report for five hours.
(下午五点时，我已经写报告写了五小时--此时强调的是写作的持续时间，而非完成。)
未来完成时和未来完成进行时，如何选择？
未来完成时（Future Perfect Simple）强调动作完成、结束、达到结果。
- By 2025, I will have finished my training.
(到2025年，我已经完成培训--此处强调结果)
未来完成进行时（Future Perfect Continuous）强调动作持续的时长或过程，直到未来某一时刻。
- By 2025, I will have been training for four years.
(到2025年，我已经接受培训四年了。)
未来进行时和未来完成进行时，如何选择？
未来进行时（Future Continuous）通常表示动作将在未来某一时刻正在发生，不特别强调总时长。
- At 8 p.m. tomorrow, I will be having dinner.
(明天晚上八点时，我正在吃晚饭。)
未来完成进行时表示一个动作会持续到未来某一时刻，已持续一段时间。
- By 8 p.m. tomorrow, I will have been having dinner for an hour.
(明天晚上八点时，我已经吃了一小时晚饭了。)
总结
未来完成进行时用于描述某些动作会一直持续到未来某一特定时刻，强调动作的连续性和持续性。
虽然这种时态出现较少，但在表达进展或时间跨度时非常有用。另外，TOEIC®考试中经常会出现未来完成进行时的相关语法题。
英语中还有其他未来时态，你也需要掌握，以下是其它未来时态课程：