Learn Hardcore Russian: Мы можем посмотреть фильм вместе вечером. - We can watch a movie together in the evening.

можем is the 1st-person-plural present form of the modal verb мочь (to be able/can). In Russian, modal verbs in the present tense express your current ability or permission to perform an action, even if that action is scheduled for later (like this evening). You’re saying “right now we are able to watch the film,” with the film-watching event to occur in the future.

Why is посмотреть (perfective) used instead of смотреть (imperfective)?

Russian has two aspects: imperfective (ongoing or habitual actions) and perfective (complete or one-off actions). посмотреть is perfective, so it frames the activity as a single, complete event (“to watch a film through”). If you used смотреть, you’d emphasize the process or habitual watching (“to be watching, could watch repeatedly”).

Why is фильм unchanged from its nominative form, and what case is it?

фильм is in the accusative case as the direct object of посмотреть. For inanimate masculine nouns ending in a consonant, the accusative form is identical to the nominative. Hence фильм → фильм.

What case is вечером, and how does it function in the sentence?

вечером is the instrumental singular of вечер, but it functions adverbially to indicate time (“in the evening”). Russian uses certain instrumental singular forms (утром, днём, вечером, ночью) as time-of-day adverbs without a preposition.

Is the pronoun мы necessary? Can it be omitted?

Because Russian verbs are conjugated for person and number, you technically don’t need мы—можем already signals “we.” However, Russian tends to keep personal pronouns for clarity or emphasis, especially in speaking. Omitting мы is possible in a very casual context: Можем посмотреть фильм вместе вечером.

How flexible is the word order? For example, could you say «Вечером мы можем вместе посмотреть фильм» or «Мы вместе вечером можем посмотреть фильм»?

Word order in Russian is fairly flexible. Moving вечером to the front emphasizes the time (“This evening…”). Placing вместе immediately after мы or можем can slightly shift the focus to “together.” The core meaning stays the same, but your emphasis changes:

«Вечером мы можем вместе посмотреть фильм.» (Focus on when.)
«Мы вместе можем вечером посмотреть фильм.» (Focus on togetherness in relation to ability.)

What nuance does вместе carry? How is it different from saying с нами?

вместе means “together” (jointly, in each other’s company) and is an adverb modifying the action. с нами means “with us” and is a prepositional phrase indicating accompaniment. While both point to group activity, вместе stresses the mutuality of the action (“we will do it together”), whereas с нами simply notes who is coming along (“the film will be watched with us,” possibly by others).