| Subject | English | Russian |
| ed. | interact with a degree of fluency and spontaneity that makes regular interaction with native speakers quite possible without strain for either party | общаться с такой степенью беглости и спонтанности речи, которая делает возможным регулярное общение с носителями языка без напряжения для обеих сторон (Level B2 of the Common European Framework of Reference for Languages) |
| ling. | native fluency | свободное владение на уровне носителя языка (каким-либо языком общения; e.g., native fluency in at least one language aside from English Alex_Odeychuk) |
| gen. | native-level English fluency | знание английского на уровне носителя языка (SirReal) |
| gen. | native-level fluency | владение языком на уровне носителя (It is said of chess that the game takes a day to learn, and a lifetime to master. In similar vein, English is reputed to be an easy beginner's language in which it is nevertheless very hard to achieve native-level fluency. LE2 Alexander Demidov) |