11. What is your mother tongue[] 1 Russian - Skip to question 13
[] 2 Not Russian, indicate language ________
12. Are you fluent in Russian?[] 1 Yes
[] 2 No
9. Language proficiency
Language proficiency means an ability to speak, read and write, or only to speak a given language.
Question 9.1. Do you know the Russian language?
"Yes" should indicate those who know Russian.
"No" should indicate those who do not know Russian.