"У мене є м'яч."
Translation:I have a ball.
In this case, it is rather some indefinite ball:
- У кого є м’яч? (Who has a ball?)
- У мене є м’яч. (I have a ball.)
In this case, some particular ball is meant and it should be known from the context which one:
- У кого м’яч? (Who has the ball?)
- У мене м’яч. (I have the ball.)
So the difference is the "є"; it means something like "there is" in English? Turkish also lacks articles, and does something similar by translating "I have a ball" as something like "my ball exists", and "I have the ball" as "[the] ball is at me".
Exactly: "У мене є м’яч" - "Benim topum var" and "У мене м’яч" - "Top bende." I love learning synergies like this.
Definite and indefinite articles do not exist in Ukrainian language. As for me this sentence could mean either so probably it should be accepted. But let's wait for other opinions.
I think in this case if there is a distinction its a rather fine one - and not really useful to teach at an early stage (what i think this is designed for, or most appropriate for) so best either to accept both (as more or less correct: perhaps. "you are almost right") or simply not use this example (until a later stage when its more useful for people to learn the finer points)