- The train arrives at Chicago.
- The train arrives in Chicago.
Chicago is a big city, so we use 'in' before a big city. However, what about the sentences above? Do we have to use 'at' or 'in'? If we think of a particular point, we use 'at'. As the train arrives at a particular point, do we have to use 'at' here? Later the train will leave Chicago. Or are both prepositions possible?