"My neighbor is Slovak."
Translation:Můj soused je Slovák.
In almost all of these exercises, the word 'Slovak' is used incorrectly. It is a noun, and should only be used to refer to a person from Slovakia. 'My neighbour is Slovak' is using the noun as an adjective, and should have the indefinite article 'a' before it. The correct adjective form is 'Slovakian'.