"The boy wants a book."
Translation:הילד רוצֶה ספר.
Did you mean את ספר? Because את is only used with definite direct objects.
The boy wants a book - הילד רוצה ספר
The boy wants the book - הילד רוצה את הספר
what's the difference between both correct options that it shows me : הילד רוצֶה ספר and הילד רוצה ספר
This is just with and without the nikud think. Sometimes the options are just odd, like when you are offered "masc." as one of the words.
The masculine is with the three dots while the feminine has the little T under צ
It seems it ignores the nikkud, so even if I write with wrong nikkud (female, vertical line perpendicular on horizontal line) purposely, it seems to accepts my answer