"ye" is the imperative form in Turkish as in "Eat!" talking to "you"
That is interesting about the Hungarian word for apple being similar to the Turkish, and a Slovak word for eats having a similar stem.
If you are talking about Jolly Ranchers, someone can definitely ask "Do you eat apple?" However, this would be a different sentence in Turkish since you are asking about apple flavored things and not a physical apple itself.
(I agree with you though....apple just needs an article)
Well, we have a similar word to "a/an", which is "bir", which you only use işt when really necessary that you are only talking about only a single apple.
Yet it's quite normal to say "bir su" (a water) instead of "bir şişe/bardak/etc. su" (a bottle/glass/etc. [of] water). There's no countable/uncountable distinction in Turkish.
This dictionary is proper to learn Turkish word : http://www.tdk.gov.tr/index.php?option=com_bts&view=bts