1. I will have finished my homework by then.
到那时候我将已经完成作业。

2. By then, the meeting will already be over.
到那时候，会议将已经结束。

3. She hopes to graduate by then.
她希望到那时候能够毕业。

4. By then, we will have moved to a new city.
到那时候，我们将已经搬到新城市。

A: Will you be ready by then?
A：到那时候你会准备好吗？

B: Yes, I will have everything done by then.
B：是的，到那时候我会把一切都完成。

1) 表示在某个未来时间点之前已经完成

2) 用于描述截止某一时刻的状态或结果

3) 强调未来某时间前的完成性

1. 到那时，在某个未来时间点之前或到那个时候。

e.g. I will be done by then.
到那时候我会完成。

2. 用于表示某事在特定时间之前已经发生或完成。

e.g. By then, she will have left.
到那时候，她将已经离开。

adverbial phrase

1. By then means at or before a particular time in the future, indicating that something will have happened or been completed before that point.