Dr John Olsson talks to Michael Rosen about how he uses forensic linguistics, specifically authorship analysis, to solve crimes including murder, false witness and hate mail. What he does is work out whether a text, email or letter is likely to have come from the person it says it is from - or whether, in some cases, it is in fact being sent by the person who has murdered them..

Family law barrister and chair of The Transparency Project Lucy Reed talks to Michael Rosen and Dr Laura Wright about the language of the courtroom and how to make family justice clearer.

Michael Rosen talks to comedian Elis James about how to make language funny. In Elis' case, this is both the English language and the Welsh language, but which is funnier?

Michael Rosen talks to academic Colin MacCabe and Dr Laura Wright about Raymond Williams' 1976 book Keywords: A Vocabulary of Culture and Society, which looks at the changing meanings of words such as 'culture', 'art', 'nature' and 'society'. Often the changes in meaning of these words reflect the changing society in which they are being used. Colin MacCabe has spent the past decade updating Williams' work, and he and his team have added some words of their own. Producer Sally Heaven.

Michael Rosen finds out how best to communicate with people with dementia. Professor Alison Wray shares her new research about the ways in which language is affected by dementia. She offers practical advice to carers, such as to respond to the feeling behind the words being used by the person with dementia rather than to the words themselves.

Michael Rosen discusses slogan T-shirts with fashion historian Amber Butchart and fashion identity commentator Caryn Franklin. What do the words we wear say about us?

Slogan clothing is having - what fashion insiders might call - ‘a bit of a moment’ right now. From longstanding British fashion house Burberry with its new contemporary text based monogram to US designer Tory Burch’s political ‘Vote’ print, the slogan t-shirt is quite literally making a statement. And it’s not just on the catwalk - we’ve all seen them – and many of us are wearing them – from ‘Nike’s ‘old school ‘Just Do It’ to ‘This is What a Feminist Looks Like’ and these chest worn or cap emblazoned messages can reveal much about the identity of the wearer. They can tell us who they are - or - who they want to be. They can reveal hopes, dreams, political views. They are an intriguing insight into the concerns and obsessions of our twenty-first century society. Or are they just a bit of word play and fashionable fun?

Produced by Nicola Humphries

Michael Rosen and Dr Laura Wright talk about the Multicultural London English (MLE) dialect with Somali born journalist Ismail Einashe. Listen to this with your fam and you'll know what Stormzy means when he talks about this wasteman ting, and find out how MLE speakers are using new forms of grammar. This programme draws heavily on research on Multicultural London English published by Paul Kerswill, University of York, UK; Jenny Cheshire, Queen Mary University of London, UK; Susan Fox, University of Bern, Switzerland, and Eivind Torgersen, Norwegian University of Science and Technology.

Producer Sally Heaven.

Lane Greene talks to Michael Rosen and Dr Laura Wright about the joys of editing and how it can improve writing. Lane Greene is The Economist's Johnson language columnist and deputy editor of books & arts. He's also a lover of a literal literally and of a well-placed colon.

Michael Rosen and Laura Wright talk to maths writer Rob Eastaway about imperial and metric measurements. How and why do they co-exist in the United Kingdom? Why are teenagers still talking in feet and inches when at school they are taught in centimetres? And where do the words 'gallon', 'tonne' 'acre' and "yard" come from? Producer Sally Heaven.

Stephen Fry talks to presenter Michael Rosen about their mutual obsession with language: the particular joys they both find in speech and in writing and how language is developing. Starting at the very beginning with Stephen's theory about where a facility with words may come from, then dashing through the joy of finding connections between words in different languages, of listening to the rhythms of music-hall patter, in telephone voicemail messages and in rap, to sketch-writing with Hugh Laurie, presenting QI, the essential seriousness of comedy, the virtues of email and text as opposed to the sheer horror of having to talk on the telephone, and one time when Stephen's famous fluency broke down..