Even if you're a Russian speaker, you could use those terms. I understand people...more people learn Russian than Ukrainian and a Ukrainian will understand that. A Ukrainian will accept that. As a matter of fact, many Ukrainians I've seen have conversations where one is using Ukrainian and the other is using Russian and they're communicating. So they understand that people study Russian, but just learning a few phrases in Ukrainian means you took the time.
A retired military service member talks about the relationship between the Ukrainian and Russian languages.