AI recreations of real people, which clone their faces, distinctive voices and all, have become so convincing that even top computer specialists are finding it hard to tell the difference between fakery and reality. Creative "deep fakes" aren't all bad - they can bring dead artists and historical figures alive, to energize museums and schools - but most uses so far have been evil: Think fake pornographic videos of your sister or daughter, or scams that bilk people out of millions of dollars. Our guest, law professor Danielle Citron at the University of Virginia, has been advising companies and government officials on how to protect the public from the terrible harm that deep fakes can cause, but executives like Elon Musk don't want to listen. Her worst fears haven't come true yet - such as a deep fake that changes an election or triggers a war - but it's hard not to expect them.

Dazzle friends with the grammar smarts you'll get from our second chat with Bryan Garner, one of America's language gurus. Finally, you're about to learn if you can - or cannot - end a sentence with a preposition; if you can use "like" instead of "as"; and if you can banish "whom" and "whomever" from your brain. Just wait until you hear Bryan's rant about lawyers' terrible writing. Speaking of which, can you guess which common five-letter word (which lawyers love) causes endless legal battles?

... we've never had so much fun debating it! Bryan Garner, one of America's grammar gurus, tells us where we're going wrong grammatically - and what we're getting right. You're sure to find (you'll surely find?) answers to some of your own burning questions, like (or is it "such as"?): should you feel bad about using adverbs? Or should you feel badly? How will this episode impact your own language? (Actually, is "impact" even a verb?) After hearing our conversation with Bryan, you might not write or speak quite the same way.

Our guest warns that some of this is so secret that even members of Congress don't know it: Past Presidents have drawn up astonishing plans to wield sweeping emergency powers, possibly including seizing control of the internet. Elizabeth Goitein, of the nonpartisan Brennan Center for Justice, has unearthed dozens of these little-known emergency presidential powers - and she says they should scare you.

In this uplifting chat, John Marks joins us again to tell how Search for Common Ground created radio and TV programs from Africa to Asia - designed to help bring former enemies together. His case studies from Burundi, Kenya and the Democratic Republic of the Congo show how Search’s broadcasts helped soothe conflicts between warring groups, and reduced the scourge of rape by rampaging soldiers. The programs obviously are no panacea, but as John says, they are “keeping hope alive.”

Trump has already shown that when he moves back to the White House, he's likely to use the strategies of dictators he admires, such as Viktor Orbán of Hungary: pack courts and agencies with ideological cronies, intimidate and harass the press, and continue to denigrate opponents as “evil,” “low IQ,” "vermin" and “enemies from within.” Harvard professor Steven Levitsky, co-author of How Democracies Die and Tyranny of the Minority, tells us why it could take years to rescue America’s democracy. Even if you heard this episode when we first posted it, we think you’ll want to listen again now that Trump is returning to the Oval Office.

John Marks says yes - and he and the organization he founded, Search for Common Ground, have made it happen. He tells us surprising stories about how they get people to listen to each other, across hard lines of hatred and suspicion: Russian and American intelligence officers, Iranians and Americans, Israelis and Arabs, Hutus and Tutsis in Africa - and more. John's memoir, From Vision to Action: Remaking the World Through Social Entrepreneurship, is like a how-to guide - filled with candid accounts of his successes and failures.

Scientist Michelle Fournet and her colleagues from the University of New Hampshire hang out with humpback whales in Alaska, recording their daily communications - and then sending whale recordings back to the giant animals to see if and how they respond. Some of her latest findings could break new ground: she can identify individual whales by their sounds. Michelle tells us the moving story of how she morphed from broke actor to internationally-respected whale researcher - and how she hopes research on humpbacks' "language" can help humans protect them.