The prepositions в and на can express a range of meanings. When the preposition в combines with the prepositional case of a noun, it is generally the equivalent of English “in” or “at.” It is generally used with locations that can be understood to have an inside and an outside.
When the preposition на combines with the prepositional case of a noun, it is generally the equivalent of English “on” or “at.” When talking about locations, на tends to be used for nouns that have an open or unbounded surface.
When expressing the idea “at” with other places, certain nouns in Russian will automatically go with the preposition в, while others will go with на:
|at school||в шко́ле|
|at the library||в библиоте́ке|
The words школа and библиотека are really buildings with an inside/outside, so they go together with the preposition в.
The preposition на is generally used in expressing the idea of “at an event” or “at a place of activity":
|at work||на рабо́те|
|at a lecture||на ле́кции|
|at a concert||на конце́рте|
Exceptional forms: There are a couple of exceptional forms for telling the location of a person/item. You have already met the form до́ма (=at home).
Another exceptional form is: на полу́ (on the floor) and в шкафу́. The stressed –у ending occurs only on a small set of masculine nouns. We will note them as we encounter such words in your book.