"You have the egg."
This is an example of an issue I mentioned in another thread, namely that of subjects and objects more or less switching places in the translation process. Such morphology might pose grammatical pitfalls. "You" is the subject in the English sentence, but in the Turkish rendering "egg" would replace it, going from object to subject to literally mean something more like "the egg is with you." I bring the matter up because I almost made the mistake of pinning the accusative suffix on "yumurta." Perhaps this sort of problem should be addressed in one of the tips and notes sections (if it isn't already).
I didn't exactly have that problem with this test prompt, but I do have to think about it to avoid that pitfall. However, I did write "Sende yumurtadır," and got it wrong. Does anyone know why this can't be considered correct? My guess is that by putting "yumurta" last, I am emphasizing it and it just doesn't make sense to do that. Is that why?
Yumurta is the subject here. In English, the subject is You, and the egg is the direct object. In Turkish, the egg is the subject, and the sentence is more like The egg is at/on/with you. As Turkish subjects don't take a suffix to indicate the definite the, the -yı is not added.
My rather too long explanation, which goes over some of the grammatical terms, with many helpful links is at this external site: https://rumnraisinblog.wordpress.com/2016/05/10/turkish-yumurta-sizde
"yı" is not used every time "the" is used in English. It is only used for a specific direct object which is their Accusative case. Now I know the English sentence has a direct object, but the literal meaning of the Turkish sentence is more like: "The egg is with/at/on you." This sentence is specifically to give the location of a specific item. This sentence is not to show possession. The subject of the sentence in Turkish does not mark the word to show us that it is definite. I can totally see why you would have thought of using the accusative case when looking at the English sentence. The Turkish sentence is constructed differently and the egg is the subject for them.