Future Tense

Once you know a verb's aspect, the future tense is decided. Imperfective verbs always form a compound future with буду; perfective verbs always use a simple future that looks like a present-tense paradigm but means the future. No mix-and-match, no auxiliary choice; the aspect alone decides.

The two futures are mutually exclusive: you never write буду прочитать (because прочитать is perfective) or читаю in a future sense (because читать is imperfective and its present-form means present). Mastering the future tense is mostly mastering aspect; see the Aspect chapter.

The verb быть (to be) has no present tense in modern Russian, only past and future. The future paradigm is regular 1st conjugation on the stem буд-, and these six forms do double duty: they're the auxiliary for the imperfective compound future, AND the standalone copula meaning "will be".

As a copula, быть's future is what English would phrase with "will be". Predicate nouns after it take the instrumental case in formal speech: он будет учителем (he will be a teacher), versus nominative in colloquial use.

The compound future is just буду conjugated to match the subject, followed by an imperfective infinitive. The infinitive is invariant; only буду changes. Use this form for ongoing, repeated, or open-ended future actions.

A perfective verb's conjugated forms look exactly like a present tense: same endings, same conjugation type, but they mean the future. There is no буду with perfectives; combining them would be a contradiction. Compare the side-by-side perfectives below.

All four examples show stem mutations or stress shifts you've met before: написать mutates с → ш and shifts the stress to root in non-я forms (напишу end-stressed, напишешь root-stressed); купить inserts -л- in the я-form (куплю); сказать mutates з → ж with the same stress pattern as написать. The aspectual prefix (here про-, на-) doesn't change what we know about how the verb conjugates.

The time expression you pair with a future-tense verb often forces the aspect. A duration ("for an hour") takes imperfective; a deadline ("in an hour, by tomorrow") takes perfective. The grammatical case of the time phrase shifts with it.

Other typical pairings: всегда, часто, каждый день → imperfective ("I'll always read…"); уже, сразу, в три часа → perfective ("I'll read [it] right away / by three"). Once you internalise the question "for how long?" vs "by when?", the choice becomes mechanical.

The placement of не is identical to other tenses: directly before the finite verb. For compound future that's буду; for simple future that's the conjugated perfective. The infinitive after a negated буду stays intact.

Russian also has lexical means for nuancing future statements, not separate tenses, but verb + infinitive constructions that add intention, beginning, or planning.

The last row is colloquial but extremely common: Russian regularly uses a present-form imperfective with a future time word ("tomorrow", "next week", "in two days") to talk about scheduled near-future events. English does the same with "I'm flying tomorrow". Both languages treat the schedule as if it were already happening.