"Sounds very exciting, but no," Donald Trump Jr. answered to a state attorney's question about whether he knows about accounting certifications, professional organizations, or accounting standards other than GAAP, which stands for "Generally Accepted Accounting Principles."

"I know nothing about GAAP," Trump Jr. said, adding, "I leave it to my CPAs."

"I'm a real estate broker," Trump Jr. said as he introduced himself on the witness stand. He testified that he began working in the family real estate business "right after 9/11," working on Trump Park Avenue and the former Sun Times building in Chicago.

State attorney Colleen Faherty tried to pressed him on his lack of accounting knowledge, prompting several objections from the defense.

Judge Engoron sustained the objections and admonished Faherty against asking negative questions.

Assistant New York Attorney General Colleen Faherty will start off the direct examination of Donald Trump Jr.

Faherty is familiar with questioning high-stakes witnesses, having led the direct examination of former Trump attorney Michael Cohen last week.

Her quick objections during Cohen's cross-examination led Trump attorney Alina Habba to accuse Faherty of trying to "throw off" her game.

A seven-year veteran of the New York attorney general's office and a former criminal defense attorney, Faherty has been a vocal presence in the courtroom since the start of the trial.

Her willingness to spar with Trump lawyer Chris Kise previously led to some heated exchanges in court, such as a sidebar when Faherty demanded Kise "be more respectful."

"No," Kise responded.

"That was rude," Faherty replied.

Donald Trump Jr. has taken the stand, where he will be the first of the former president's children to testify.

Before taking the stand, Trump Jr. sat while news photographers snapped pictures.

"I should've worn makeup," he quipped.

One week ahead of her planned testimony, Ivanka Trump has appealed Judge Engoron's decision to require her to testify in person at the Trump Organization's fraud trial.

Ivanka Trump's lawyer Bennet Moskowitz asked an appellate court to decide whether Engoron has jurisdiction to compel her testimony and whether the trial subpoenas issued by the New York attorney general were properly served.

Ivanka Trump, who is not a defendant in the case, is currently scheduled to testify next Wednesday as the final witness in the attorney general's case before the defense presents its case.

The second day of testimony from the defense's expert accounting witness prompted an argument between attorneys for the two sides over the basic question of what the case is about -- leading defense lawyers to make their fourth unsuccessful request for a directed verdict to end the trial.

The arguments came toward the end of direct testimony by accounting expert defense Eli Bartov, who asserted the New York attorney general's case lacked merit because there was no evidence of any fraud on Trump's statements of financial condition, and that any errors about the values of Trump's properties were unintentional and therefore immaterial.

When the defense attempted to question Bartov about those values, state attorneys objected -- prompting defense attorney Christopher Kise to leap from his seat.

"If they don't call anyone to dispute our values, how have they proven their case?" Kise said.

Judge Arthur Engoron, in a pretrial ruling, already decided that Trump conducted a decade's worth of business using fraudulent financial statements, and state attorney Kevin Wallace suggested that Bartov's findings do not change those findings.

"You can't use false statements in business. That's what the summary judgment decision is all about. I think it is pretty much what the rest of this case is about," Engoron said in response to Kise's question.

Kise argued that if the attorney general doesn't prove what Trump's asset values should have been, the case is a "completely rudderless ship" that needs to be "moored to some sort of standard."

"You can't just say it's a misstatement because you feel like it," Kise argued.

"The standard is truth," Engoron responded.

The exchange prompted Trump's legal spokesperson, Alina Habba, to make the defense's fourth motion for a directed verdict, arguing that Engoron is "wasting our time" if he won't consider their expert testimony.

"They have not proven their case. They haven't," Habba said in her request for a directed verdict.

"Denied," Engoron said within seconds of the request, without hearing a response from lawyers for the New York attorney general.