In a verbal soft-shoe act scheduled to play twice daily throughout the summit, White House spokesman Marlin Fitzwater and Soviet Foreign Ministry spokesman Gennadi Gerasimov yesterday sparred gently with journalists, made jokes at each other's expense and mostly avoided questions with a deftness that appears to come more with the job than the nationality.

Dubbed "the Marlin-Gennadi show" by Reuter news agency, the duo struck many of the 1,000 or so journalists in the J.W. Marriott grand ballroom as being more alike than different. Part of the reason was that Gerasimov made it clear that, even in a second language, he is a first-class public-relations man.

"Which one was the capitalist?" CBS White House correspondent Terence Smith asked after their first hour-long news conference. "Which one was smooth, well-tailored, speaking as though he was straight out of Madison Avenue? This is a whole new kind of Russian."

ABC's Sam Donaldson agreed, saying, "We're all intrigued with this wily Russian." Gerasimov, wearing a bright red tie that perked up the television camera crews, quickly exhibited a subtle and sophisticated wit, the kind that can forestall some of the toughest questioning, at least for a while.

Noting that the Soviet press contingent was far outnumbered by the White House press corps, Gerasimov suggested to Fitzwater: "You answer all the questions which are put in English, and I will answer all the questions in Russian."

Fitzwater replied: "I'll answer the easy ones. You answer the hard ones."

If the Soviet spokesman was showing that he could sidestep questions as easily as his U.S. counterpart, Gerasimov also was given some lessons of his own about how the U.S. press corps treats an official at the podium.

For example, when Fitzwater mispronounced the name of Adm. William J. Crowe Jr., chairman of the Joint Chiefs of Staff, a bass voice from the television section loudly corrected him.

When longtime White House journalist and gadfly Sarah McClendon asked a question, she made it clear that she would not take a runaround from a Soviet any more than she does from a U.S. spokesman.

McClendon asked Gerasimov to release the list of publishers, businessmen and political leaders invited to meet privately with Gorbachev this week.

"Well, I'll ask the embassy to release the list," he said, somewhat dismissively.

"You know, sir, well . . . that's not enough," McClendon boomed from the back of the massive room. "We don't get any answer from the embassy, most of us . . . . I'm depending on you to get it for us."

"I"ll try, I'll do my best," Gerasimov said as journalists grumbled that he sounded as though he had been trained by Fitzwater.

Although Gerasimov was as smooth as Stolichnaya for most of the briefing, he hit a rough patch when a journalist asked about Mrs. Gorbachev's schedule.

"Part of her schedule will coincide with the general secretary's schedule," he said. "Also, she will visit certain places in Washington, and she will be invited to tea parties," he added, perhaps hoping that would end it.

"Is she going shopping?"

"It is not on the program," he said to laughter.

"Fill us in. What is on her schedule? What is she doing?" he was asked.

"She will be pretty busy. As I've told you, part of the program will be together, and then, for instance, the signing ceremony and meetings which General Secretary Gorbachev is going to have with representatives of the American public," he said "Also, she is invited to a tea party to the White House and other social engagements."

That was too much for a press establishment accustomed to being fed names, times, places and dates for such matters.

"Glasnost," someone boomed to general laughter.

For all of the high marks journalists gave Gerasimov for his first Washington co-briefing, several suggested that his urbane wit will soon wear thin if he does not provide information to go with it.

As Michael Putzel, Moscow correspondent for the Associated Press, reported yesterday about Gerasimov:

"Off stage, he shows little inclination to be polite as he brushes off a stream of reporters seeking answers they have been unable to obtain from his staff, which rarely answers phone calls and practically never has information to impart."

Putzel reported that, when Gerasimov was pursued down the hall by reporters yesterday, he ignored their queries, asking Fitzwater, "Do we have an escape route?" Fitzwater gestured toward a side door, Putzel said, and the pair moved briskly down a utility corridor as aides barred reporters from following.

Such a historic event naturally brings out journalists with a sense of history. Charles McDowell, a columnist for the Richmond Times-Dispatch, said he covered the visit of Soviet premier Nikita Khrushchev in 1959 when the press corps was less unwieldy.

"But, about this time in the proceedings, Khrushie was down on a farm staring straight into the eyes of a hog," McDowell recalled. Waving his hand toward the Marriott press center, with its pink walls and massive oval crystal chandeliers, McDowell said: "This is pretty uptown by comparison."

Anchorman Bernard Shaw, working to fill time on Cable News Network as Gorbachev's plane was landing, said that, at the time Soviet premier Nikita Khrushchev came, President Dwight D. Eisenhower " was taking a lot of flak from his secretary of state, John Foster Dulles . . . . Dulles didn't like the idea of the summit."

Dulles had died in May, two months before Khrushchev was invited to the summit.