Learn Russian: В этот кабинет можно входить?

Можно is an impersonal word meaning 'it is allowed' or 'one may.' In Russian, you don't need a subject like 'I' or 'you' when asking about general permission. You simply pair можно with an infinitive verb, like входить (to enter). If you wanted to specify 'May I enter?', you would add the dative pronoun мне: В этот кабинет мне можно входить?

Why is it в этот кабинет instead of the prepositional case в этом кабинете?

Because the verb входить (to enter) implies motion toward a destination. When the preposition в indicates direction or motion into something, it takes the accusative case. Since кабинет is a masculine inanimate noun, its accusative form looks exactly like its dictionary (nominative) form. If you were already inside the office doing something, you would use the prepositional case в этом кабинете.

Why use the imperfective verb входить instead of the perfective войти here?

When asking for permission using можно, Russian speakers often use the imperfective aspect. Using входить focuses on the general rule or the action itself: 'Is entering allowed?' If you used the perfective войти, it would focus more on a single, specific result: 'Can I step inside right now?' Both are possible, but входить is a very standard way to ask if an action is permitted.

Why are the words можно входить at the end of the sentence?