To express location at/in and direction to a place, you usually use the preposition в, e.g. в Москвљ (Prep.) 'in Moscow', в Москвџ (Acc.) 'to Moscow'. To express 'from' a location, you usually use из, e.g. из МосквІ (Gen.) 'from Moscow.' However:
For some nouns, you have to use на for 'to/at' and с for 'from.'
We call these на-nouns.
на концљрте (Prep.) at the concert на концљрт (Acc.) to the concert
с концљрта (Gen.) from the concert
Many such nouns denote occasions and events, like урћк 'lesson', занїтие 'class', концљрт 'concert', etc. Some of them have two uses, one in the sense of 'event' and the other in some other sense. For example, in the sense of 'event' (i.e. a class) the word урћк 'lesson' is a на-noun, but in the sense of 'a portion of a textbook' it is not.
To find out if a particular noun requires на, you have to look it up in the Dictionary. This task may be somewhat simplified, if you remember the following guidelines:
  • all events are на-nouns (e.g. свђдьба wedding)
  • the points of the compass are на-nouns (e.g. сљвер North)
  • all islands and peninsulas are на-nouns (e.g. Сахалќн)
  • most flat open spaces are на-nouns (e.g. плїж beach)
Here is a list of some common, but perhaps less obvious, на-nouns:
рабћта work завћд, фђбрика factory пћчта post office
кџрс course факультљт school, division (in a college, etc.)
џлица street проспљкт avenue бульвар boulevard
рІнок market плћщадь (town) square стадићн stadium
вокзђл station (bus, train, etc.) мћст bridge останћвка stop (bus, train, etc.)
этђж floor, level пћл floor (part of a room) крІша roof
вІставка show, exhibition демонстрђция parade парђд military parade
Чтћ бІло в ітом урћке? What was in that lesson (in the textbook)?
Чтћ бІло на ітом урћке? What happened at that lesson?
ТІ ходќла на егћ лљкцию? Did you go to his lecture?
На лљкции бІло скџчно. The lecture was boring (It was boring at the lecture).
Сђша сегћдня не ходќл на рабћту. Sasha didn't go to work today.
Сђша сегћдня не ходќл на занїтия. Sasha didn't go to classes today.
Сђша всё ещё на концљрте? Is Sasha still at the concert?
Сђша тћлько что вернџлся с концљрта. Sasha just got back from the concert.