I've heard spoken Ukrainian and understood
It is a little bit complicated with Ukrainian. E.g., now I speak the Ukrainian that is actually not my native language (or strictly speaking, not "my native Ukrainian"). As a child I spoke, like all people around, literary Halychyna Ukrainian, HU, (the language of I. Franko, Osyp Makovey, Mykhaylo Pavlyk etc.), but when I started to go to school, it was the period when the standard Ukrainian language (SUL) based on the Poltava dialect was introduced, which for us (especially schoolchildren) was a sort of another language (both grammatically and lexically).
Here are only some points as an example:
a) we used Present Perfect structures along with the Past Indefinite saying e.g. "Ya mayu to vzhe zrobleno/napysano, prochytano" along with "Ya to vzhe prochytav/napysav/prochytav" etc. meaning "I have already done that" and "I did this". Nowadays you can hardly hear Present Perfect structures - they may not be even understood by the new generation.
b) the reflective particle "self", "sya", was a separate word and it was moveable in a sentence, so you could say: "Ya vzhe sya vmyv" or "Ya vzhe vmyv sya" (I have already washed myself) etc., which is not the case in SUL.
c) hundreds of words have been replaced in all areas, here are some from the area "School, Education" (these were the first words we had to change for new ones): "atrament, bibula, lawka, geografiya, radyrka, studiya na universyteti, vyshkil, hodyna" for new ones: "chornylo, promokartka, parta, heohrafiya, rezynka, nawchannya w uniwersyteti, nawchannya, urok".
And for years, we had been using these two our "languages": one at home and with friends and neighbours, and the other one - at school, then at the Institute and work - till the time the HL has almost stopped to be used. Separate words are still used, but with the aim to spice your language, or to show that one is from Halychyna when one meets Halychyna people outside it. But no more.
But paradoxically, people in Poltava, whose language we speak here now, usually do not speak this language, but prefer Russian. So, my "first Ukrainian" you, FlaglessPole, would have understood even better.