Original sentence: It is bordered on the west by the Pacific Ocean and on the north and east by the Atlantic Ocean; North America and the Caribbean Sea lie to the northwest.South America is a continent of the Americas, situated entirely in the western hemisphere and mostly in the southern hemisphere
Edited sentence: South America is situated entirely in the western hemisphere and mostly in the southern hemisphere is considered a continent or a subregion of a greater continent, America; bordered on the west by the Pacific Ocean and on the north and east by the Atlantic Ocean; North America and the Caribbean Sea lie to the northwest