It is a question, that's why you use "do you have...?" here. In Russian the words order are the same in affirmative and interrogative sentences.
- У меня есть молоко. - I have milk.
- У меня есть молоко? - Do I have milk?
- У тебя есть молоко. - You have milk.
- У тебя есть молоко? - Do you have milk?
Does this sound like a question to you? Because I can't distinguish this from "You have milk". Do Russians stress their questions differently? I mean, do they stress a question by using higher sounds at the last word. Or do they not and the computer voice is doing it right?
"Ест" is form of verb "to eat" ("есть") used with he/she/it in present time: "он ест" (he eats). No more meanings.
"Есть" has at least 3 meanings in one word.
1) To eat. "Я люблю есть яблоки" (I like to eat apples).
2) Form of verb "to have" ("иметь", "обладать") used in present time as in the sentence.
3) "To be" which is usually omitted. Just realized that in Russian there is one word for "to be" and "to have" as one can think about existence of something as being posessed by the universe or by someone you don't specify.
Examples: "Есть ли смысл...?" (Does it make sense...?) You also can say "Имеет ли смысл...?"
"Есть традиция..." (There is a tradition...)
"Человек есть мера всех вещей" ("Of all things the measure is man") (Protagoras)
It's grammatically correct. The contractions that are mostly used like "You've got" are fine and should be accepted as a valid answer, but when writing academically, contractions aren't very well received. Now I don't know how academic Duolingo should or can be considered though.