What cases “Падежи” we use after the preposition “за”

Answer

Hi! With this preposition 2 cases can be used, Accusative and Instrumental.

The Accusative case is used:
- In the meaning of direction with position verbs: "Поставить стул за стол".
- In the time meaning, "to finish something within a time limit": "Закончить работу за два дня".
- In some expressions: "спасибо за", "благодарить за", etc.

The Instrumental case is used:
- In the meaning of place: "Стул стоит за столом".
- With some verbs; "смотреть за кем?", "следить за кем?", etc.