This is not a problem just for Orthodoxy - it happens in other groups.
My home Community is very very Ukrainian - the first came over years ago - the surviving members of the original Group are over 90 !
It was men who came and once they were allowed to, they worked on the land and some eventually married local girls - and taught their wives a limited amount of Ukrainian. Children came along - and were taught a little Ukrainian , but were not taught to read it
According to my GodPapa they learned 'kitchen Ukrainian'
Result - the children moved away as they grew up and became young people [ as indeed young people tend to do ]
We now have a generation of 90 yr olds who are literally dying [ there are about 6 left who still come to Church every week ] Very few of their wives speak Ukrainian . Their offspring who do attend can only cope with transliterated Ukrainian but have learned the Liturgy by parroting it [ i.e. imitating the sounds ]
This generation now have given birth to another younger group - who again are , on the whole , not being taught the language.
I'll give an example - 2 years ago a boy of about 12 was helping me put out the candles on the candle stands after Liturgy. and since we were alone I asked him how much of the Liturgy he could understand [ I'd seen him fidgeting all through ] - he looked round to see no-one could hear us - and muttered " not a lot " I said " anything ?" and he shook his head looking ashamed. I gently asked if he would like a copy of Liturgy in both languages so he could follow the prayers as we were chanting them.
His eyes lit up then he said " I'll need to ask my mum " I had a quiet word with Mum and she was happy - she's young , Ukrainian with a not very good command of English , comes to Church maybe once every 2 months. I printed out the bilingual copy that I use - side by side on the same page - much easier to follow that way.
When I brought it into Church the following week in case he was there , I told our priest at the time [ resident in the Country for 18 years but with English like my spoken Ukrainian - virtually nil ] his comment was that the boy's Mother wants him to learn it in Ukrainian - so my slightly sharp comment was - " She can teach him the words in Ukrainian but can she really explain the meaning ? "
I really think we have to be realistic about the use of language. I can manage Liturgy in Ukrainian for 90%of the time - because of my struggles I always say the Creed quietly in English which it's being chanted in Ukrainian - and the same with the Pre-Communion Prayer .
We have a fledgling Mission now that we have served the 5 times - numbers are poor despite our efforts - maybe 2 or three coming ! The Students aren't interested - nor are the young professionals there either. We know of 14 young professionals - but one has come twice - the others not at all
Father is young and enthusiastic , but let down by folk who talk a lot, demand a lot and won't do.
During a Feast Day Liturgy during the week in my home Parish - I'll travel there if possible , and it's probably just Father and me present - so we Serve in English - it's good for his English though I do have to prompt him at times
It's a real problem - I see that our parish needs to go English usage - everyone there speaks English in their day-to-day life.
Now where I am today [ I go home tomorrow ] it's a parish of young Ukrainians - lots of children who grow up speaking and understanding Ukrainian - and English - and sometimes Russian at home - and also learn Gaelic at School. There is also a Ukrainian Saturday School for them not far away as well. I've no problems with them Serving solely in Ukrainian - and actually they do use some English !