(1) big指具体事物的大小,强调比正常形体的标准大,既可用在普通场合, 也可用在正式场合。它可用来指人的身材高大或"长大了",还可表示"伟大","重要"之意。如:
Can you lift up this big stone? On the last day I made a big decision.
(2) large特别强调远远超过标准的大,指体积、面积、容积、数量之大。如:
A whale is a large animal. A large crowd collected at the gate of the theatre.
(3) great除了表示数量体积之大外,又指抽象的程度,意味着伟大性,重要性, 优越性;常用于抽象或无形的东西;用于有形的东西时,常带有"伟大","大得令人吃惊"等意思,含有一定的感情色彩。如:
China is a great country with a long history. He was one of the greatest scientists.