great

In reference to the size and extent of concrete objects, great is highly formal and even poetic, suggesting also that the object is notable or imposing, large is only somewhat formal, and big is the most general and most colloquial word: a great oak; a large tree; a big tree; great plains; a large field; a big field. 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).