big 常用词，使用广泛，较口语化。多指体积、重量或容量等方面的“大”，有时也用于描写抽象之物。
large 普通用词，含义广，指体积、面积、容量、数量以及程度等方面的大，具体或抽象意义均可用。
great 普通用词，可指具体东西的“大”，但更常指事物的重要，人的行为、品格的伟大等，带一定的感情色彩。
grand 侧重指盛大、绝大，有气派。
参考例句
1. So the merchants have a large market. 所以商人有一个很大的市场。
2. Application: Primary use in large machinery packing. 用途：主要用于大型机械包装。
3. One of the facilities our students have is a large library. 我们学生所拥有的设备之一是一所大图书馆。
英英解释
n.
1. a garment size for a large person
2. above average in size or number or quantity or magnitude or extent
3. fairly large or important in effect; influential
4. ostentatiously lofty in style
5. generous and understanding and tolerant
6. conspicuous in position or importance
7. having broad power and range and scope
8. in an advanced stage of pregnancy adv.
1. at a distance, wide of something (as of a mark)
2. with the wind abaft the beam
3. in a boastful manner
