WINDOW ROCK, Ariz. (AP) – A Navajo Nation presidential candidate must either take a test or testify to demonstrate whether he’s fluent enough in the tribe’s language to qualify for its top elected post, a chief hearing officer said Friday.

Richie Nez of the Navajo Office of Hearings and Appeals is hearing arguments in a case that alleges Chris Deschene lied on his candidate application and is violating a tribal law that says candidates for president of the largest American Indian reservation must speak fluent Navajo.

Deschene says fluency is hard to define but that he has communicated well in Navajo with voters on the campaign trail.

On Friday, Nez rejected requests to dismiss the grievances filed by two of Deschene’s challengers in the primary election. But he also declined to rule in their favor, which would keep Deschene off the ballot.

Instead, Nez said he must first decide the candidate’s language ability according to a standard set by the Navajo Nation Supreme Court. The high court last week sent the case back to Nez, saying the Navajo language is sacred and cannot be disregarded as a qualification for the presidency.

Outside the hearing, Deschene’s supporters marched carrying a large campaign banner and listened to the proceedings via a live Internet stream. Seating inside was limited to about three dozen people.

For most Navajos, the language issue goes beyond the election. It centers on how to preserve what the federal government once tried to eradicate and what parents were ashamed to teach their children.

The Navajo language is a defining part of the tribe’s culture, said to have been handed down by deities. It’s woven into creation stories and ceremonies, and spoken during legislative sessions, in dinner conversations and during Miss Navajo pageants.

More people speak Navajo than any other single American Indian language, according to the U.S. Census Bureau.

“Yes, it’s part of the election, but it’s an overall big picture of us as a nation, whether we honor our clans, our language, how to incorporate that,” said tribal member Jaynie Parrish, 35. “This is a very big turning point for our community.”

The appeals office previously dismissed the grievances against Deschene as untimely. But the tribe’s Supreme Court said the office must consider their merits.

The tribe’s election office and the Office of Hearings and Appeals have no test to determine fluency. The grievances against Deschene were the first to challenge the language requirement since it became tribal law in the 1990s.

Nez said he asked the tribe’s Department of Dine Education for help devising a test that would adhere to the high court’s ruling, which said candidates must smoothly and skillfully speak the language and be able to understand Navajo speakers and engage in conversation.

Deschene declined to take a fluency test Thursday.

“No one in the history of the Navajo Nation has had to take a proficiency test to be elected,” said his campaign manager, Lambert Benally. “And we feel that is discriminatory. It’s unfair.”

Nez initially said Deschene was within his rights to decline to take the test, but attorneys for former presidential candidates Dale Tsosie and Hank Whitethorne disagreed.

The 27,000-square-mile reservation is larger than any American Indian land base, covering sections of Arizona, New Mexico and Utah. Almost two-thirds of the 300,000 Navajos live on the reservation, which is rich in natural resources and has some of the Southwest’s most iconic landscapes.