In short

A verbal adverb (дееприча́стие) packs a second action by the same person into one word. The imperfective form in -я/-а means “while / by doing” (a process going on at the same time); the perfective form in -в/-вши means “having done” (an action finished first). It never changes its ending, and its doer must be the same subject as the main verb - otherwise it “dangles” and is wrong.

The rule

A verbal adverb is not the English gerund (“reading is fun”). It is an adverb made from a verb: it tells you how / when / why the main action happens, by naming a secondary action that the same subject performs. It is indeclinable - one fixed form, no gender, number or case.

There are two types, and the choice is purely about aspect and timing:

• Imperfective = a background process running simultaneously with the main verb: Чита́я кни́гу, я отдыха́ю. = While reading a book, I relax.
• Perfective = an action completed first, then the main action follows: Прочита́в письмо́, она́ запла́кала. = Having read the letter, she burst into tears.

The key rule (and the famous mistake). The verbal adverb has no subject of its own - it borrows the subject of the main clause. So both actions must be done by the same person. Test it by rewriting with и (“and”): Прочита́в письмо́, она́ запла́кала = Она́ прочита́ла письмо́ и запла́кала. If that rewrite is impossible (different doers), you may not use a verbal adverb - use a когда́ / потому́ что / е́сли clause instead. The classic error is a “dangling” verbal adverb whose real subject is something else: ❌ Чита́я кни́гу, зазвони́л телефо́н (the telephone wasn’t reading).

Negative: just add не: не зна́я (not knowing), не поду́мав (without thinking).

Register. Verbal adverbs compress subordinate clauses and belong to written / formal style. Recognise them readily; use them carefully.

Forms & patterns

Imperfective - take the они́-form of the present tense, drop -ут/-ют/-ат/-ят, add -я (or -а after ж, ш, ч, щ). Reflexive verbs keep -сь:

Perfective - from the past-tense stem (drop -л), add -в after a vowel (reflexive -вшись); verbs in -чь, whose masculine past has no -л, take -ши, and prefixed verbs of motion take -я:

Note: the older form -вши (прочита́вши) is now archaic/colloquial for non-reflexive verbs - use -в. But reflexive verbs must keep -вшись (верну́вшись), and the -ши of испёкши is a different, fully standard ending.

Examples

Common mistakes

• Чита́я кни́гу, зазвони́л телефо́н -> Когда́ я чита́л кни́гу, зазвони́л телефо́н - “dangling”: the phone wasn’t reading. If the doers differ, use a когда́-clause, not a verbal adverb.
• Прочита́в письмо́, мне ста́ло гру́стно -> Прочита́в письмо́, я загрусти́л - the main clause needs a real subject (я) that does both actions; a dative «мне» can’t be the reader.
• Я отдыха́ю, прочита́в кни́гу -> Я отдыха́ю, чита́я кни́гу - for a simultaneous action use the imperfective -я; perfective -в means the action finished first.
• Пиша́ письмо́, он слу́шал ра́дио -> Когда́ он писа́л письмо́, он слу́шал ра́дио - some verbs (писа́ть, пить, ждать, бежа́ть) have no imperfective verbal adverb; rephrase with a clause.
• Прочита́вши статью́, он замолча́л -> Прочита́в статью́, он замолча́л - the -вши ending is archaic for non-reflexive verbs; standard is -в (reflexive keeps -вшись).

Tips

• Same-subject test: rewrite the sentence with и (“and”). Поза́втракав, он ушёл = Он поза́втракал и ушёл. If one subject can’t do both actions, drop the verbal adverb and use когда́ / потому́ что / е́сли (lesson 37).
• Suffix = timing. -я/-а = “at the same time” (a process, НСВ); -в = “first that, then this” (finished, СВ). Match the suffix to the aspect of the verb you start from.
• Indeclinable. Unlike participles (lesson 45), a verbal adverb never changes ending for gender, number or case - if you see an agreeing ending, it’s a participle, not a verbal adverb.
• A few have frozen into ordinary adverbs and prepositions: мо́лча (silently), не спеша́ (unhurriedly), су́дя по (judging by), несмотря́ на (despite). These no longer need a matching subject.