将来完成时 (Future Perfect)

past -------- now -------- future point -------- future

                            ↑
                    在将来某时间点之前要完成的动作

这种时态用于描述在将来某个时间点之前将要完成的动作。

语法形式

将来完成时的构成是：主语 + will have + 过去分词

• 肯定句：主语 + will have + 过去分词

  • I will have finished.
  • She will have graduated.

• 否定句：主语 + will not have + 过去分词

  • I will not (won't) have finished.
  • She will not (won't) have graduated.

• 疑问句：Will + 主语 + have + 过去分词？

  • Will you have finished?
  • Will she have graduated?

应用场景

1. 将来某时已完成的动作

用于描述在将来某个时间点之前已经完成的动作。

示例：

• By next month, I will have finished my thesis. (到下个月，我将已经完成论文。)
• By the time you arrive, I will have cleaned the house. (在你到达之前，我将已经打扫好房子。)

2. 表示持续到将来的动作

用于描述到将来某个时间点为止已经持续了多长时间的动作。

示例：

• By next year, I will have worked here for ten years. (到明年，我将已经在这里工作十年了。)
• By the end of this month, they will have been married for 25 years. (到本月底，他们将已经结婚25年了。)

3. 预测或推测

用于对将来某个时间点之前可能发生的事情进行预测。

示例：

• The plane will have landed by now. (飞机现在应该已经降落了。)
• By the time we get there, the movie will have started. (等我们到那里时，电影应该已经开始了。)

与其他时态的对比

将来完成时 vs 一般将来时

将来完成时强调动作在将来某个时间点之前的完成状态，而一般将来时只是表示将来要发生的动作。

示例：

• I will finish the work tomorrow. (一般将来时 - 明天完成工作)
• I will have finished the work by tomorrow evening. (将来完成时 - 到明天晚上之前就完成工作)

将来完成时 vs 现在完成时

将来完成时是以将来某个时间点为参照点，而现在完成时是以现在为参照点。

示例：

• I have worked here for five years. (现在完成时 - 到现在为止已工作五年)
• By next year, I will have worked here for six years. (将来完成时 - 到明年将已工作六年)

常见用法和例句

1. 与时间表达搭配

常与以下时间表达搭配使用：

• by + 将来时间点
• by the time + 从句
• before + 将来时间点

示例：

• By 2025, we will have built a new factory.
• By the time you wake up, I will have left.

2. 表示推测

用于对将来某个时间点的情况进行推测：

• The meeting will have finished by now.
• They will have arrived home by this time.

3. 描述成就或目标

用于描述在将来某个时间点之前要达到的目标：

• By the end of this year, I will have saved enough money for a car.
• By graduation, she will have published three papers.

注意事项

1. 将来完成时通常需要一个明确的将来时间点作为参照：

   • ✔️ By next week, I will have completed the project.
   • ❌ I will have completed the project. (缺少时间参照点)

2. 在时间状语从句中，要用现在完成时而不是将来完成时：

   • When I have finished (不是 will have finished) my homework, I will call you.
   • After she has graduated (不是 will have graduated), she plans to travel.

3. 将来完成时常与以下时间表达一起使用：

   • by then
   • by that time
   • by the end of...
   • before...
   • when...