1.) Portuguese is the majority language of South America, by a small margin. Spanish, with slightly fewer speakers than Portuguese, is the second most spoken language on the continent.
2.) French
3.) The primary differences lie in the division of labor or factors of production and the mechanisms that determine prices. The activity in a market economy is unplanned; it is not organized by any central authority but is determined by the supply and demand of goods and services.
4.) I have no idea