Megan Whelan looks at how language shapes - and is shaped by - our understanding of the world, with Dr Sasha Calhoun, Professor Paul Warren and Associate Professor Stephen Epstein.

What does it mean when something is 'lost in translation'? Why isn't there an English word for 'schadenfreude'?

In part two of Great Ideas, Megan Whelan looks at how language shapes - and is shaped by - our understanding of the world.

"Schadenfreude may well have come into the English language because there wasn't a word that expressed that particular concept," Professor Paul Warren says.

"English, of course, is a very avid borrower of words from other languages. There's this strange idea that languages borrow from each other, I think English borrows but never gives back."

Dr Sasha Calhoun says our need to express the things that are most important to us has a big part to play in what words come into being in different languages.

"Then the languages themselves get to work on what is expressed. But you can find all sorts of lovely examples."

She cites an Australian Aboriginal word for the concept of sitting by a fire and rubbing the hands of the person next to you so both share in the warmth of the fire.

So did language evolve from the need to express an idea like that, or simply from the need to warn others of hazards?

"That's the 65-million dollar question," Dr Calhoun says. One theory is that language arrived alongside greater human cooperation.

"Particularly, the need for mothers to pass things along to their children.

"So the need to be able to teach methods and ways of living and ways of being in the world that were increasingly complex became something that mothers needed to pass on to children."

It's also not just words, it's the sounds that make up words. Take, for example, words that are synonyms for 'small' - 'wee' and 'tiny' have similar sounds.

"I think every language studied has some form of onomatopoeia," Stephen Epstein says.

"But some languages, and where things get interesting is Korean, have what we might call 'memetic' words."

"So they don't represent a sound, but they might represent something that you see."

He says that in Korean words like "twinkle, sparkle and glitter" have different vowel sounds depending on the size or intensity.

And then there's the question of what counts as a word - apocryphally, various languages from around the polar region have "50 words for snow"…

Go to this episode on rnz.co.nz for more details