1.First,not one language,but local languages.Which was made into one in 19th century.Ukrainian language - Wikipedia
en.wikipedia.org
If they didn't exist, who spoke Ukrainian then, and why did Russians ban teaching it?
Time traveling Austrians?
Don't tell me they had shotguns and sunglasses.
Yet Palestinian Arabs and all the nearby Arab countries still don't even try to have their separate languages, they all speak Arabic.
Second,people used many languages when nations do not existed yet,becouse they consider themselves as somebocy subject.
We poles become nation,but only for gentry,in 13 th century.Yet,polish languages existed before that.
For our case,ukrainians on Wołyń considered themselves as tsar subjects till 1928,when Poland started teaching them ukrainian and hired teachers for that.They even replaced old pops who prayed for tsar with new ones who prayed for Ukraine.
Result - in 1943 they genocided more then 60.000 poles in most possible cruel ways,when their teachers and pops lead them to slaughter polish children.
.If we do not teach them anytching,they would still consider themselves as tsar subjects,and kill few people for their riches.
2.Becouse it is sacred language of Koran,and they are all good muslims.Most muslims speak arabic for that reason,even if they are not arabs.
Just like palestinians.