But the use of Kurdish is not simply a matter of linguistic comprehension. Sometimes it is a form of diplomacy. One of the most aggressive legal investigations against Baydemir concerned a series of public statements he made in Kurdish in March 2006. In a battle that month between P.K.K. militants and Turkish soldiers, 14 Kurds had been killed. Diyarbakir exploded in mass demonstrations that ultimately became violent. Baydemir begged the crowd  in Turkish  to settle down, to refuse further violence, to go home and rest. The crowd chanted P.K.K. slogans, like “Teeth to teeth, blood to blood, we are with you Ocalan,” referring to Abdullah Ocalan, the head of the P.K.K. whom Baydemir, as a lawyer, had defended after his capture in 1999. Desperate to subdue the crowd, Baydemir switched to Kurdish. “You claimed your identity,” he told them. “With burnt hearts, you claimed your people and your pain. We are also with you. Be sure of this. But for the sake of peace, for the sake of your success, we have to listen to each other under the leadership of the party”  the Democratic Society Party, or D.T.P., Turkey’s only legal “pro-Kurdish” party. “We fear,” he went on, “that this mobilization from now on will harm our nation and our people. From now on, we all will go back to our homes quietly.” Sixteen people were killed in the rioting that subsequently spread across the southeast and into Istanbul. The mandate  the ordeal  of a mayor in a Kurdish town was clear: a kind of internal mediation of the highest order, the challenge of connecting to the hearts of the Kurdish population while governing according to the laws of the state.

Nearly all of the prominent Kurdish politicians accused of language violations are members of the D.T.P. But the latest front in the party’s legal battles is not crimes against the alphabet but the status of the D.T.P. itself. On Nov. 16, Abdurrahman Yalcinkaya, chief prosecutor of the Supreme Court of Appeals, applied to the Constitutional Court to ban the D.T.P., arguing that it is merely a suit-and-tie-clad front for the P.K.K. “The party in question has become a base for activities which aim at the independence of the state and its indivisible unity,” the prosecutor wrote in his statement.

This move to ban the pro-Kurdish party, likely to last several months in court, is in some ways less surprising than the fact that the D.T.P. made it to Parliament at all. In the past several years, at least four Kurdish parties have been banned or forced to dissolve in Turkey, always under the accusation of supporting the P.K.K. and threatening Turkey’s unity. But the D.T.P. has been different. In last July’s elections, it became the first Kurdish party to have a strong presence in Parliament in more than a decade. It did so by running its candidates as independents in order to get around a 10-percent minimum (of the total vote) that a party would need to achieve in order to actually win seats. Supporters saw its victory as a chance to address Kurdish issues in Turkey through democratic means. D.T.P. members took great pains to assert their desire to work within the law, to give voice to the economic, social and cultural concerns of their constituents and to bridge the deep chasms between their group and Turkey’s old guard, which is represented by the Republican People’s Party and the Nationalist Action Party.

But from the new Parliament’s opening session in August, the D.T.P.’s presence set in motion a circus of hostile and even juvenile behavior. At the helm of Parliament, the neo-Islamist Justice and Development Party has been the most neutral. But throughout the late summer and fall, Turkish society was captivated by play-by-play scrutiny of who would shake whose hand and who would be invited to whose parties. Some representatives of nationalist and secularist camps took to calling their D.T.P. colleagues “separatists.”

Since D.T.P. members first entered Parliament, they have been urged by everybody from the prime minister to the European Union to the United States to condemn the P.K.K. Prime Minister Recep Tayyip Erdogan and the leaders of other parties have stated repeatedly that until the D.T.P. does so, it will not be trusted. D.T.P. leaders have attempted to distance themselves from the P.K.K. without directly condemning the group: in public statements, they constantly reiterate that they are against separatism, do not want to divide the Turkish state and oppose all violence. In the autumn, D.T.P. leaders began calling fallen Turkish soldiers “martyrs,” as the military and the rest of Turkey’s establishment have always done. But that wasn’t nearly enough after an early-October attack killed 13  the worst strike by the P.K.K. in years. Turkish television channels broadcast continuous gut-wrenching footage of soldiers’ mothers collapsing over coffins and uniformed officers comforting them. An intense climate of national mourning set in, along with a focus on national security that Kurdish activists feared would obliterate any hope for cultural reforms.

Aysel Tugluk, a young female leader of the D.T.P. and a one-time member of Ocalan’s defense team, sounded exhausted when she spoke at a conference in Istanbul later that month. She started her talk with a long string of condolences for all those who died, then went on to say: “If you force the D.T.P. to condemn the P.K.K., you deny us the possibility to take initiative in a way that could turn out to be effective.” But she added that if Kurdish cultural demands were met, the D.T.P. would be able to condemn “any force that deploys violence” and that the most important step right now would be for Kurds to be allowed to express themselves in their native language. “After 30 years, we still have violence,” Tugluk said, “so I think we should stop and ask, What was our mistake? The P.K.K. has to be taken into account from a sociological point of view; it is the result of the nonsolution to the Kurdish issue: we have to focus on the origins of that issue.” Ayhan Aktar, a sociologist at Istanbul’s Bilgi University, described the situation to me more bluntly: “If the D.T.P. condemns the P.K.K., they won’t ever be able to go to Diyarbakir again; they will get beaten up on the street by some hotheads when they set foot in town.”