someone who spoils the fun of others
тот, кто портит веселье других (tot, kto portit vesel'ye drugikh)
"Don’t be a party pooper, join the fun!"
"Не будь занудой, присоединись к веселью!" (Ne bud' zanudoy, prisoedinis' k vesel'yu!)
in a hostile or dangerous situation
to have a casual conversation about unimportant topics
to have influence or importance
peace follows a period of trouble
to become aware of something important
to have both positive and negative effects