GrammarModal verbs

Many meanings like can, must, need, or may are most commonly expressed using impersonal words.

These are short words like можно, нельзя, нужно, надо. They are one of the most used words in Russian and do not change and do not have a subject like normal verbs.

Then there's also должен, which is a short-form adjective and works a bit differently.

The impersonal words

These are:

• мо'жно мо́жно (can, may, allowed)
• нельзя' нельзя́ (not allowed)
• ну'жно ну́жно (need, have to; more formal)
• на'до на́до (need, have to; more colloquial)

Main structure

The typical structure for all four is:

• (person in Dative) + impersonal word + infinitive

Examples:

• Тебе можно войти? Тебе́ мо́жно войти́? (Are you allowed to enter?)
• Мне нужно работать. Мне ну́жно рабо́тать. (I need to work.)

The person is often optional if it is clear from context:

• Надо идти. На́до идти́. (We / I have to go.)

The person in Dative

To say who needs, is allowed, or must do something, you use the Dative case. Here are the personal pronouns in Dative:

Example: Мне нужно идти. Мне ну́жно идти́. (I need to go.)

You can also use the person's name in Dative: Ивану можно войти. Ива́ну мо́жно войти́. (Ivan may enter.)

Permission / possibility: мо'жно Мо́жно

мо́жно means it is allowed or it is possible.

• Мо́жно войти́? (May I come in?)
• Здесь мо́жно кури́ть. (You may smoke here.)
• Мне мо́жно уйти́? (Am I allowed to leave?)

можно is used whenever something is allowed or possible. It is often used for asking or giving permission, similar to “may” or “can” in English. It is neutral and very common in everyday speech. Unlike English, you do not need a subject like “I” - the sentence can stay impersonal. If you want to specify who is allowed, you use the Dative (e.g. мне, тебе́).

Note: You usually do not say не мо́жно. Instead, Russian uses the separate word нельзя (see the following section).

Prohibition: нельзя' Нельзя́

нельзя́ means not allowed or must not.

• Здесь нельзя́ паркова́ться. (You cannot park here.)
• Мне нельзя́ пить ко́фе. (I must not drink coffee.)

It is the negative form of мо́жно. While мо́жно means “it is allowed / possible”, нельзя́ means “it is not allowed / forbidden”.

• Мо́жно войти́? (May I come in?)
• Нельзя́ входи́ть. (You must not enter / No entry.)

нельзя expresses prohibition or strong impossibility. It means that something is not allowed, forbidden, or should not be done. It is stronger than simply saying “cannot” - it often implies a rule, restriction, or negative consequence. It is widely used in signs, instructions, and warnings (Нельзя́ кури́ть – No smoking). With a person in Dative, it can also mean something is not allowed or not advisable for someone personally (мне нельзя́).

Necessity: ну'жно ну́жно and на'до на́до

Both ну́жно and на́до mean need to or have to.

• Мне ну́жно рабо́тать. (I need to work.)
• На́до идти́. (We have to go.)

Difference:

• ну́жно → neutral, slightly more formal
• на́до → more common in spoken language

Negative:

• Мне не ну́жно рабо́тать. (I do not need to work.)

ну́жно expresses a need or necessity in a neutral, matter-of-fact way. It often sounds slightly more formal or objective than на́до. It can describe personal needs (мне ну́жно) or general requirements (ну́жно сде́лать). It does not strongly imply obligation or external pressure - just that something is required or necessary.

на́до also expresses need or necessity, but is more conversational and informal. It is very common in spoken Russian and often used for everyday situations. Compared to ну́жно, it can feel more immediate or practical (“we should / we have to do this now”). In many cases, на́до and ну́жно are interchangeable, but на́до is preferred in casual speech.

Without a person (general statements)

Very often, people omit the person and speak generally:

• Нужно работать. (One needs to work.)
• Можно войти. (You may enter.)
• Нельзя шуметь. (No noise allowed.)

One more: до'лжен до́лжен

До́лжен means must / be obliged to and is not an impersonal word, but a short-form adjective (from до́лжный). It expresses a stronger, more personal obligation than ну́жно or на́до.

In contrast to мо́жно, нельзя́, ну́жно, на́до, до́лжен:

• has a Nominative subject (я, он, etc.), not Dative
• agrees in gender and number like an adjective

Forms:

Negative: Я не должен это делать. (I must not / should not do this.)

Difference to нужно / надо

• Мне нужно работать. (I need to work - neutral necessity)
• Я должен работать. (I must work - obligation, duty, expectation)

In short:

• нужно / надо → situation requires it
• должен → I am obliged / expected to do it

Practical application

Using these impersonal words and related forms, you can express the most important modal meanings:

can / may (permission)

(Dative) + мо́жно + infinitive

Мо́жно откры́ть окно́? (May I open the window?)

must not / cannot (prohibited)

(Dative) + нельзя́ + infinitive

Нельзя́ кури́ть. (You cannot smoke.)

need / have to (neutral necessity)

(Dative) + ну́жно / на́до + infinitive

Мне ну́жно учи́ться. (I need to study.)

Мне на́до в туале́т. (I need to go to the toilet.)

must / be obliged to (strong obligation)

Subject + до́лжен / должна́ / должны́ + infinitive

Я должна́ учи́ться. (I must study - female speaker)

Related verbs

There are two verbs that express similar ideas:

• мо'чь мочь (to be able to)
• хо'теть хотеть (to want)

мочь can

Both мочь and можно mean “can”, but they are used differently:

можно → permission or general possibility

Можно открыть дверь? (Is it allowed?)

мочь → ability or capability of a person

Я могу открыть дверь. (I am able to do it.)

хотеть (want)

Хотеть is a common verb and expresses desire. The difference between хотеть and нужно/надо is a nuance, but in the end it's the same as the difference in English between "want" and "need":

• Я хочу спать. ("I want to sleep" - I'm sleepy - desire)
• Мне надо спать. ("I need to sleep" - it's late, I have work tomorrow - necessity)

Summary

• Russian often expresses modal meanings using impersonal words instead of verbs.
• Impersonal words are можно (allowed), нельзя (not allowed), нужно/надо (need).
• Impersonal words use the structure [Dative + impersonal word + infinitive].
• There's also the short-form adjective должен (must) which is used to express obligation.
• должен has the structure [Nominative + должен/должна/должны + infinitive].