Hello Kirill, I think that this is a Russian saying but it doesn't translate well into English directly. I think I would reword it as: "If only young people knew and old people were able to (the world would be a better place)." Best wishes Bob

I think it is possibly supposed to read.... If only the youth knew what the old people know ... It sounds to me that it may be referring to the wisdom of older people and suggesting that if young people had that wisdom it would be beneficial to their lives and the choices they made. However, this is just my interpretation. :)

What about: "If only the youth knew, if only the eldery could"? I feel like "only" makes the sentence stronger, not sure though, not a native English speaker.

What you are looking for is probably 'If youth but knew, if age but could'.

да, для русских смысл понятен. Yes, for russian people it is easy to understand