"A first name is not a last name."
Translation:שם פרטי הוא לא שם משפחה.
Another correct answer is "שם פרטי אינו שם משפחה". I don't quite understand what "אינו" means or when to use it. And in which lesson did it first appear?
We know that אין means "there is not". So אינו would mean "he (it) is not" or "there is not to him (it)", sort of like הוא לא.