-но/-то

This construction is a powerful tool in Russian for shifting focus away from the agent of an action.

1. Formation:
It uses the short passive participles in the neuter singular. This form is invariable, meaning the ending never changes to agree with any nouns or pronouns in the sentence. These participles are almost exclusively formed from perfective verbs (совершенный вид) to describe a completed result, though a few imperfective forms exist in fixed, colloquial expressions (e.g., Об этом не раз говорено). The suffix depends on the verb stem:

• -но: Used for most verbs (e.g., сказано, решено, написано).
• -то: Used for verbs ending in -оть, the suffix -ну- (e.g., тронуть -> тронуто), -ыть, -ереть (e.g., запереть -> заперто), or certain monosyllabic roots ending in a vowel (and their prefixed derivatives) (e.g., закрыто, взято, прожито).

Crucially, unlike standard passives, this impersonal construction can even be formed from intransitive verbs to describe a general state or result. However, this is restricted to specific semantic groups. These include verbs prefixed with на- that leave a physical trace or result in an environment (e.g., наслежено - tracks have been left, накурено - it is smoky), as well as unprefixed verbs of motion and state in colloquial speech (e.g., здесь не хожено - no one has walked here, не езжено - no one has driven here, сижено - someone has sat here). In Standard Russian, it cannot be formed from reflexive verbs (verbs ending in -ся).

2. Syntax and Features:

• Tense: In the present tense, no auxiliary verb is used (zero copula), and the participle stands alone (e.g., Здесь накурено). To form the past or future tense, use the neuter singular of the verb быть (было or будет) with the participle (e.g., было сказано, будет сделано).
• Dative Experiencer: The person affected by or receiving the action is often in the dative case, but this is usually preserved from the underlying verb's government (e.g., велеть кому-то, сказать кому-то). You cannot simply attach a dative experiencer to any impersonal passive (e.g., you cannot say Мне накурено). Example: Нам велено - We were ordered.
• Genitive Case: Because this construction cannot take a nominative subject or accusative direct object, Russian heavily relies on the genitive case to express what is being affected, especially for quantities (e.g., Здесь наметено снега - A lot of snow has been swept up here) and in negative sentences (e.g., Об этом не было сказано ни слова - Not a word was said about this).
• Prepositional Phrases and Oblique Objects: These impersonal participles frequently govern prepositional phrases or oblique objects inherited directly from the underlying verb (e.g., послать за доктором -> За доктором послано - The doctor has been sent for; забыть об этом -> Об этом было забыто - This was forgotten about).
• Infinitive Complements: These predicates are frequently followed by an infinitive (e.g., Решено продать дом - It was decided to sell the house).
• Instrumental Agent: The agent performing the action can be expressed in the instrumental case. This is highly standard in formal or bureaucratic contexts (e.g., Комиссией установлено - It was established by the commission) or with unknown agents (e.g., Здесь кем-то наслежено - Tracks were left here by someone).

3. Usage and Register:
Unlike a personal passive where the participle agrees with a subject (e.g., 'Дверь закрыта'), the impersonal passive has no grammatical subject. It is widely used for official decisions ('Решено...'), public signs ('Закрыто', 'Занято'), and describing resulting atmospheres. It is very common in formal writing and bureaucratic Russian, but also appears in fixed idiomatic expressions in daily speech.