The first week of January saw him leave England and travel to Jamaica. The first week of March saw his return.

那篇文章有点太长了，我告诉网友最简单、最实用的理解方法：

1. 把时间主语翻译成时间状语。说明事件在这个时间发生。

2. 把“人”翻译成主语，动作（动词或具有动词性质的名词）翻译成谓语动词。

第一句，主语是“他”（him），谓语部分是“离开英国，前往牙买加”。第二句，主语还是“他”（his），谓语是“回来”（return）.

如果你查词典，词典有see这种用法的英英解释。例如《韦氏高阶》动词see释义的第14条：

[+ object] : to be the place or time in which (something) happens (为某事发生的时间或地点）

The city has seen a lot of growth in recent years. [=the city has grown a lot in recent years]

This year has seen a drop in profits. [=profits have dropped this year]

The last decade saw many technological advances.