A former Philly mayor grilled a first-time candidate about how the government works. It was awkward.

Do you know what Philadelphia’s sinking fund is? How about the administrative board? Not so sure?

Neither was mayoral candidate and grocer Jeff Brown — that is, until Tuesday night, when former Mayor Michael Nutter quizzed the first-time candidate about some of the inner workings of city government in front of a live audience.

The ex-mayor posed questions like: “How many times have you read the home rule charter?” (Answer: zero times start-to-finish, but advisers have run through the highlights), and “Have you ever been stopped by the police?” (Answer: once in college for having a temporary plate on a new car.)

The thorough grilling delivered by Nutter was part of an hour-long interview of Brown, one of a series hosted by the news website the Philadelphia Citizen. Each candidate agreed to answer job-interview-like questions by a panel of three experts, including Nutter. At the first installment last month, the former mayor started off by announcing he wouldn’t run for his old seat.

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The terse back-and-forth between Nutter and Brown stood in contrast to the dialogue between Nutter and candidate Maria Quiñones Sánchez, a former Council member who served during the former mayor’s tenure, in a session immediately after. Questions to her ranged from: “What are your three most important goals?” to one probing why challenges facing her Council district haven’t abated.

In an interview Wednesday, Nutter — who said he has not decided if he will endorse a candidate — said he was trying to tailor his questions to the interviewee, and he wanted to see if Brown is “becoming a student of this enterprise.”

“This is a fundamental, complete lack of understanding of the structure of the government,” Nutter said. “The public deserves someone who actually knows and understands government. It’s very different than running a grocery store.”

Brown’s campaign manager, Jimmy Cauley, said in a statement in response that Brown is “clearly the front runner and his message of change is resonating.”

“His record speaks for itself and we’ll let the people decide,” Cauley said.

The exchange between Nutter and Brown included several painfully awkward moments, starting with Brown, a longtime ShopRite proprietor, saying that his father had a grocery store in West Philadelphia and that Nutter’s parents were among the customers.

“They didn’t live anywhere near your store,” Nutter said.

He went on to ask Brown a series of probing questions, including who is advising him about how municipal government works.

Brown responded that about two years ago, he hired former Mayor John F. Street to work for nine months as an adviser (Street recently endorsed former Controller Rebecca Rhynhart). Brown said he consulted with Street on matters including the Philadelphia home rule charter, the city’s governing document that is akin to a constitution and lays out the powers a mayor has at their disposal.

Nutter went on: “What’s the most important position you’ll hire?” Brown replied: chief of staff and managing director, saying: “I’m going to lead those two people, they’re gonna manage all the people.”

“What are you gonna do?” Nutter shot back.

“Manage them,” Brown replied, “and really, this is a more than 50% external job. ... It’s a cheerleader job. It’s a visionary job.”

“It’s a little more than that,” Nutter said.

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Nutter quizzed Brown further, asking if he knew what the city’s sinking fund is used for. (It’s money set aside to pay off debts or bonds.) Brown said it’s money set aside for a rainy day. Nutter asked if he knows what the administrative board is, and Brown did not. (The board consists of the mayor, managing director, and finance director, and shapes organizational and procedural policy.)

Larry Platt, the cofounder of the Philadelphia Citizen who moderated the discussion, said that while Nutter was “extremely hard” on Brown, the idea was to conduct a job interview and the candidates “should take tough questions.”

“These people are vying to be the CEO of a $6 billion corporation,” he said. “So I was happy with the level of discourse, awkward though it may have seemed.”

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Staff writer Chris Brennan contributed to this article.