big

In reference to the size and extent of concrete objects, big is the most general and most colloquial word, large is somewhat more formal, and great is highly formal and even poetic, suggesting also that the object is notable or imposing: a big tree; a large tree; a great oak; a big field; a large field; great plains. When the reference is to degree or a quality, great is the usual word: great beauty; great mistake; great surprise; although big sometimes alternates with it in colloquial style: a big mistake; a big surprise; large is usually not used in reference to degree, but may be used in a quantitative reference: a large number (great number).