about

about, around, round

这些词均有“在周围、在附近”之意。
about: 既可表静态，也可表动态。
around: 主要用于美国，静态或动态均可。
round: 主要用于英国，多半指动态。

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。

形容词 about:

1. on the move
   同义词：astir

副词 about:

1. (of quantities) imprecise but fairly close to correct
   同义词：approximately, close to, just about, some, roughly, more or less, around, or so
2. all around or on all sides
   同义词：around
3. in the area or vicinity
   同义词：around
4. to or among many different places or in no particular direction
   同义词：around
5. in or to a reversed position or direction
   同义词：around
6. in rotation or succession
7. (of actions or states) slightly short of or not quite accomplished
   同义词：just about, almost, most, all but, nearly, near, nigh, virtually, well-nigh

1. I dropped the key somewhere about here.
   我把钥匙掉在这儿附近了。
2. Tell me all about it.
   告诉我关于这件事的一切。
3. The children are rushing about.
   孩子们到处乱闯。
4. I dropped my key somewhere about here.
   我把钥匙掉在这附近某个地方了。
5. He was about to start.
   他即将动身。
6. It is about six o'clock now.
   现在是六点钟左右。