Elon.io is an online learning platform
We have an entire course teaching Russian grammar and vocabulary.
Questions & Answers about Мы должны пить воду.
Why is должны used here, and what does it mean?
должны is the short-form plural of the adjective должен, functioning as a modal verb meaning “must” or “have to.” Short-form adjectives in Russian agree in number and gender with the subject and can express necessity. Since мы (“we”) is plural, you use должны rather than должен (masculine singular) or должна (feminine singular).
Why is пить in the infinitive form instead of a conjugated verb?
After modal expressions like должны, Russian uses the infinitive to indicate the required action. Here пить (“to drink”) remains in the infinitive, just as in English you say “must drink” rather than “must we drink” with a conjugated form.
Why is воду in the accusative case, and not вода?
The verb пить (“to drink”) takes a direct object in the accusative case. Feminine nouns ending in -а change that ending to -у in the accusative, so вода becomes воду.
Could we drop мы and just say должны пить воду?
While Russian often omits subject pronouns when context is clear, должны is a short-form adjective and doesn’t carry clear person/number marking the way verbs do. Omitting мы here would sound incomplete. You need мы to show who is obligated.
What’s the difference between мы должны пить воду and using нам нужно or нам надо?
- Мы должны пить воду uses a true modal idea of obligation (“we must/have to”).
- Нам нужно пить воду or нам надо пить воду are impersonal constructions with the dative нам, meaning “we need to drink water.”
Nuance: должны often feels slightly stronger or more formal than нужно/надо.
Why is the verb imperfective пить, not the perfective выпить?
Imperfective пить speaks to a general, habitual, or ongoing action (“to drink” in general). Perfective выпить implies completing the action once (“to drink up”). If you said Мы должны выпить воду, it would mean you must finish drinking that water, rather than the general need to drink water.
How do you turn this into a question: “Should we drink water?”
Insert the question particle ли after должны:
Должны ли мы пить воду?
You can also keep the declarative order and use rising intonation:
Мы должны пить воду?
Could we say Мы обязаны пить воду instead?
Yes. обязаны is another short-form adjective meaning “obliged.” Мы обязаны пить воду is a bit more formal or emphatic but essentially interchangeable with мы должны пить воду.
Is the word order in Мы должны пить воду fixed?
The neutral order is Subject – Predicate – Infinitive – Object (S–P–Inf–O). You can shuffle for emphasis (e.g., Мы должны воду пить to stress воду), but the given order is the most natural and unmarked.
Where is the stress in должны, and how is it pronounced?
должны is pronounced [dɐlˈʐnɨ], with the stress on the second syllable: долж-НЫ.