Interslavic Language | Will Bulgarian, Polish and Croatian understand a CONSTRUCTED LANGUAGE? | #1

I did give some thought whether your native language makes it easier or harder to learn others, but all I have is anecdotal cases from my life. I wonder if there are any scientific studies on the topic. E.g. a curious thing I noticed is the frequent complaint about Latin being very hard to learn because of the seven grammatical cases, three genders and morphology -- words just don't stay the same. As native Russian speaker I find these things absolutely normal and easy to understand, but I can image this must be a nightmare after English. Slavic languages you mention are very curious in how different yet how similar they all are. One of the most impressive thing I saw with respect to learning languages is the Interslavic language [1]. Apparently if you speak any of Slavic languages you can understand it quite well, even though you usually are completely lost with most of the other Slavic languages. You still need to learn to speak it, but the fact that you understand foreigners with zero training just blows my mind. Feels like you awakened the memory of your ancestors of something. [1] ▶ this video

They did some experimentation with a Czech/Slovak colleagues, but those two languages are quite close already. I'm not sure if they ever got the chance to practice with a slavic language that is further removed from Polish. I recall watching this video at the time (which might have been their inspiration to start learning it). ▶ this video

There was recently a video posted of Interslavic being used with a Bulgarian, a Polish and a Croatian. ▶ this video