Chechens
In 1989, 73.4% spoke Russian, though this figure has declined due to the wars for a large number of reasons (including the lack of proper education, the refusal to learn the language, and the mass dispersal of the Chechen diaspora due to the war). Chechens in the diaspora often speak the language of the country they live in (English, German, Arabic, Polish, Georgian, etc.).
Terek Cossacks
In Chechnya and Ingushetia however, the situation was different. There was a long-running ethnic conflict between the Chechen returnees and the Russian settlers of the region. Before 1989, the Russians had dominated all parts of government as well as the workforce, but then this reversed with the "Chechen revolution" in 1990, where the Chechen and Ingush majority took control of the ruling of their homeland. Russians were left jobless as able Vainakh took their places. The Russian language remained in many schools and the Russians of the republic were not immediately made victims.