Is Bolivia the cheapest country of South America?

[utsavviradiya]

The Grammarly app suggests using the preposition 'in' instead of 'of' in the sentence "Is Bolivia the cheapest country of South America?" and I wonder why. As a point of information, Bolivia is a landlocked country located in South America. I am aware that the preposition "in" can be used, but why not "of"?

 

[jutfrank]

When talking about which continent a place lies in geographically, 'in' is the appropriate preposition to use. Imagine that South America represents a border inside which there are several different countries. The preposition 'in' gives this meaning of being physically inside the border.