The negotiations about the entry of the EU have never officially stopped or came to an conclusion. But it is unlikely that given the current state of affairs Turkey is going to be a member soon, because the possible member ship is now officially viewed as unrealistic by the EU.
Most opponents viewed the member ship of a muslim country as problematic due to large cultural differences, also the status of divided Cyprus was a show stopper. The refusal to admit the genocide also might have had some influence on it, too.
The thing is that Turkey was always being treated on double standards: the option to join the club was already back then in the 1960s outlined, but in reality none of the major players in the EU ever wanted to see that happen.
On the other hand Turkey is an important NATO ally, and a buffer for Syrian refugees. So the EU is paying lots of money to Erdogan to keep the Syrian refugees in his country, instead of letting them go to the EU. So this gives Erdogan a lever and bargaining chip over the EU whenever they want to do something which he dislikes.
In previous times in reailty Turkey was governed by its military. The military had points on the agenda, one was to fight Islam and its politic influence. This was in line with the views of the founder of modern Turkey, Kemal Atatürk, who was strong opponent of an Islamic state, banned many muslimic items and influences in Turkey and made it a secular state. Turkey is one of the view states with a muslimic majority which was more or less a democracy, safe guarded by its military. Then came Erdogan, and Erdogan first tried to enter the EU, and he really made first some progress, for example lessening the pressure on the Kurds amongst other things. But when he came to the conclusion that the EU is playing games with him and he'll never enter the club, he turned around 180 degrees and started to appeal to the stricter muslims in his country and scrapped many points which Atatürk implemented to battle Islam. For example in Turkey it was forbidden to wear a veil in universities; Erdogan scrapped that rule. And many others. He also tried to cut down the influence of the military, which was the real power in the state.
You see, back in 2004 when the start of membership negotiations with Turkey became imminent, for example in Germany the conservative parties in their electional campaigns were strictly against Turkey being a full member of the EU. Some supporters of the Turkey member ship back then argued that Turkey right now is on a tipping point - it can either develop more in direction of the West or Islam, and if we don't pull them now over to us we'll might get the opposite, an Islamic theocracy in Europe. While this has not happened yet, the direction now is quite clear and the advocates were right on that. But personally I guess that Turkey back then was still miles away from a member ship anyway.
Instead they wanted to offer them something like EFTA light - an option the Turks would have never really been satisfied with from the beginning.
Or in short a cynical conclusion about the behaviour of the West: the Turkey is a very important NATO ally, due to its size and location. It's just a pity that it is being populated by so many muslims. So they are getting treated like that strange and fugly uncle in your family during christmas dinner no one wants to sit nearby: he's invited just because, but never getting treated like the rest.
And part of the reason why Turkey is like it is today is the EU's fault, because stuff was always delayed instead of speaking the truth.
