Tim Kaine knows what it’s like to debate Mike Pence.

Four years ago, when Senator Tim Kaine of Virginia faced off against Mike Pence at the vice-presidential debate, the encounter put two drastically different debate styles on display: Mr. Pence came across as mild-mannered and more formal while Mr. Kaine, a litigator by training, was more of an attack dog, with a tendency to interrupt and talk over Mr. Pence. Even as Mr. Pence made little effort to directly rebut attacks against Donald Trump, Mr. Kaine tried at nearly every turn to offer praise for his running mate, Hillary Clinton.

Ahead of this year’s vice-presidential debate on Wednesday between Senator Kamala Harris of California and Mr. Pence, The New York Times spoke to Mr. Kaine about what Ms. Harris should expect, how the news of Mr. Trump’s coronavirus diagnosis might affect the vice president and whether Mr. Kaine is offering Ms. Harris any advice.

The following is an edited and condensed version of the conversation, which was conducted on Friday, after Mr. Trump announced he had tested positive for the coronavirus but before he was hospitalized.

What is it like debating Mr. Pence? What advice are you going to give to Senator Harris?

I’ll answer the first question, not the second one because we’re in conversation about advice, but why would I make that public?