Danger, you might learn something.

I'm sure you have wondered, like me, why all the countries in south America speak Spanish except for Brazil where they speak Portuguese?

Now I have an answer thanks to the book I'm reading at the moment called American Colonies by Alan Taylor.

Turns out that when Spain and Portugal bickering over stuff in the Atlantic (territory, resources, slaves etc) the Pope eventually had to step in and cool things down (luckily Portugal and Spain were both devoutly Catholic).

At this point all that was known of the Americas was Hispaniola (what is now Haiti and the Dominican Republic) and some surrounding islands.

So the Pope said that everything east of halfway to Hispaniola would be for Portugal (Africa mainly but also possible routes to Asia), and everything west of halfway would be Spanish.

Further exploration revealed that South America stuck out further into the Atlantic ocean, crossing that midpoint, and so it became Portuguese.

There you go.