nearly

almost, nearly, about, approximately, around, roughly

这些副词均有“大约，差不多”之意。
almost: 指在程度上相差很小，差不多。
nearly: 与almost含义基本相同，侧重指数量、时间或空间上的接近。
about: 常可分almost和nearly换用，但about用于表示时间、数量的“大约”时，实际数量可能多也可能少。
approximately: 多用于书面语，指精确度接近某个标准以致误差可忽略不计。
around: 多用于非正式场合，常见于美国英语。
roughly: 指按粗略估计，常代替about。

副词 nearly:

1. (of actions or states) slightly short of or not quite accomplished
   同义词：about, just about, almost, most, all but, near, nigh, virtually, well-nigh
2. in a close manner
   同义词：closely, intimately

1. He nearly poked me in the eye with his stick.
   他的竿子几乎扎着我的眼睛。
2. The descent down the mountain took nearly two hours.
   下山差不多花了两个小时。
3. The sea covers nearly three-fourths of the world's surface.
   海洋几乎占地球表面的四分之三。
4. We are nearly related.
   我们是至亲。
5. The matter concerns him nearly.
   这事与他有密切关系。
6. The train was nearly full.
   火车差不多满座了。