The adverbial participle

An adverbial participle is an unchangeable verb form that shows an additional action alongside the main one and answers «как? что делая? что сделав?». The imperfective form is simultaneous with the main action and is built from the present stem plus «-а/-я»: «читая», «говоря», «слыша». The perfective form shows consecutive actions; it is built from the past stem plus «-в, -вши, -ши»: «прочитав», «вернувшись», and for some verbs with «-я»: «войдя», «принеся». An adverbial participle always refers to the subject of the sentence, so «Читая книгу, у меня заболела голова» is wrong. An adverbial phrase is set off by commas; a single imperfective adverbial participle at the end («Мы шли напевая») and one inside a set expression («слушали открыв рот») are not. «Не» is written separately («не читая»), but together when the word is not used without «не» («ненавидя», «недоумевая»).