that's conjugation for 2nd person singular.
edit: I read your question again. If we have two parts with two subjects, sometimes we don't conjugate the second one. It is not ideal but it is OK. As in "Ben bakkaldayım, sen hastanede"
I would very much like to have an answer to that question too... I translated bakkal with"shop" and it was not accepted... but it might be a problem with my English (what is the difference between a shop and a store supposed to be? size?), less than with the Turkish world bakkal...
The stores that sell only fruit and vegetables are called "manav". (The total numbers of "bakkal"s have dropped a lot in the last decade, due to increased numbers of "süpermarket"s.)
A convenience store could be "büfe", which is actually a buffet.
A butcher's shop is "kasap"
The person, who sells flowers, is called "çiçekçi", and the shop where they sell flowers is "çiçekçi dükkanı". However, in colloquial, "çiçekçi" is used for both the people and the places.
The same relation can be established for many others. For example,
• ayakkabı (shoes) →ayakkabıcı,
• kitap (book) →kitapçı,
• balık (fish)→balıkçı,
• tamir (repair)→tamirci,
• eski (old, secondhand)→eskici,
• su (water)→sucu,
• mobilya (furniture)→mobilyacı,
• gözlük (glasses) →gözlükçü,
• telefon (telephone) →telefoncu,
• bilgisayar (computer)→bilgisayarcı,
• döner →dönerci,
• kuyum (jewelry)→kuyumcu,
• emlak (real estate) →emlakçı,
• benzin (benzine)→benzinci,
• saat (clock) →saatçi,
• diş (tooth)→dişçi,
• oyuncak (toy)→oyuncakçı,
and so on.