"You do not have milk."
Translation:У тебя нет молока.
"Молока" is the genitive form of "Молоко", and "Нет" requires the genitive form.
Why "у тебя нет есть молока" not accepted? I thought "есть" was simply not obligated but still fine?
Shouldn't it be "У тебя нету молока."? I am a Native Russian speaker and that is how you say it. You could say it both ways.
Тебя is the genetive case form of ты. Changing the pronoun reflects what is happening, answering the question "who has what?" (Тебя has молока)
I suppose you, like me, have also selected У вас нет яблока. At first glance I read it as у вас нет молока and selected it as well.. but on a second reading I saw that it was actually яблока, referring to apples. Hope this helps :)
У (genitive) нет (genitive)
У тебя нет молоко(-о+а)
У тебя нет молока