"Julia is a child."
Translation:जूलिया एक बच्ची है ।
Perhaps this is because I've only known Hindi informally, but I've always thought that "Julia is a child" and "Julia is the child" has no actual difference when writing it in Hindi since there are no articles; context tells you which one is implied.
True. But since the English sentence mentions 'a', we should add 'ek' when translating to Hindi.
What is the difference between बेटी and बच्ची? or are they interchangeable?
Beti (बेटी) is daughter. Bacchi (बच्ची) means any female child. Can be used as daughter too depending on the context. Kinda like in French where "fille" means girl but "ton fille" means your daughter.