take a closer look at the "Hey". it appears only on the "apple" (התפוח). but not in the "sweet". in heb in order to definite a phrase we add "Hay" to the object and its adjective. if there is more that one adjective we also add "Ve" " before.
the apple is sweet = HaTapuach Matok || the sweet apple = HaTapuach HaMatok || the sweet red apple = HaTapuach HaMatok VeHaAdom