He asks no questions during the arguments in court.

NY Times story:

In the 20 years that ended in 2008, the justices asked an average of 133 questions per hourlong argument, up from about 100 in the 15 years before that.

"The post-Scalia court, from 1986 onward, has become a much more talkative bench," Professor Johnson said. Justice Antonin Scalia alone accounted for almost a fifth of the questions in the last 20 years.

Justice Thomas has said he finds the atmosphere in the courtroom distressing. "We look like 'Family Feud,' " he told the bar group.

Justice Thomas does occasionally speak from the bench, when it is his turn to announce a majority opinion. He reads from a prepared text, and his voice is a gruff rumble.

He does not take pains, as some of his colleagues do, to explain the case in conversational terms to the civilians in the courtroom. He relies instead on legal Latin and citations to subparts of statutes and regulations.
...
Justice Thomas routinely issues sweeping concurrences and dissents addressing topics that had not come up at argument.


~ Becky in Tucson