We used to sign off letters using "yours faithfully" or "yours sincerely", then email came along and it was all "kind regards" and "best wishes". Now, it seems, we hardly sign off at all. With so many forms of written communication- email, text, Twitter, What's App- what new etiquettes are emerging, and where are 'digital natives' simply getting it wrong? Emma Gannon is author of Ctrl, Alt, Delete: How I Grew Up Online, and hosts the podcast of the same name. Producer Sally Heaven.

Vocal coaches Gillyanne Kayes and Jeremy Fisher, authors of This is a Voice, give Michael Rosen a workout. They get him to read against natural pitch and intonation, which proves nearly impossible, and make him match his speaking pace to a walk around the studio. What we do with our consonants and our ability with a tongue twister also turn out to play a part in the ways in which we speak.

Michael Rosen and Dr Laura Wright are back with a new series of Word of Mouth, and appropriately enough they're starting with Hellos. And greetings. Former diplomat Andy Scott has greeted people in more than 60 countries, and he's written a book about his experiences called One Kiss or Two? The origins and psychology of greetings provide a rich subject and by the end of the programme they may all even reach an agreement about how many times to kiss..

From The Red Lion to the Bucket of Blood, how did your local get its name? Michael Rosen asks Word of Mouth's resident linguist Dr Laura Wright about her research into pub names. And guest Eddie Gershon explains how the JD Wetherspoon pub chain goes about naming new pubs.

Produced by Mair Bosworth.

Michael Rosen and Dr Laura Wright talk to geneticist Steve Jones about how language is used to talk about genetics, and how genetics influences language.

Producer Sally Heaven.

Michael Rosen finds out what the rest of society can learn about communication from people on the autism spectrum, by getting an insight into a different worldview. He meets Alis Rowe and Helen Eaton from the Curly Hair project. Producer Sally Heaven.

The writer Robert Macfarlane (author of Landmarks, The Old Ways, The Wild Places and Mountains of the Mind) believes that the language we use to talk about nature is itself at risk of becoming an endangered species. A 2016 research paper by Cambridge University conservationists found that eight-to 11-year-old schoolchildren were 'substantially better' at identifying common Pokemon characters than common species of British wildlife.

Over the past 10 years, Macfarlane has been gathering a 'word-hoard' of thousands of terms for nature, landscape and weather, in the hope of preserving, enriching and diversifying our language for the living world. He shares some of his favourites with Michael Rosen and Dr Laura Wright and talks about why its so important to celebrate the language we use to talk about the natural world.

Produced by Mair Bosworth.

Lifelong Arsenal supporter Michael Rosen and football-uninterested Dr Laura Wright talk to Adam Hurrey about the language, and in particular, the clichés of football. Football is a linguistic microclimate, with coinages shooting into everyday speech: back of the net!

Malorie Blackman, author of Noughts and Crosses, talks in depth to Michael Rosen about language: the writing that has shaped her and how she's used language in her own influential work. Her lifelong love of reading was fostered by the libraries she went to as a child. If she had to choose between being a reader and being a writer, she says, she'd choose being a reader..

Michael Rosen and Laura Wright ask Great British Menu judge Andi Oliver and author of The Flavour Thesaurus Niki Segnit how they describe the flavours of food. Niki describes coriander and lime as "the wooh woohs in 'Sympathy for the Devil' - completely and utterly indispensable". But grapefruit, on the other hand, is "standoffish".. She brings a cheese and a mystery item into the studio for Michael and Laura to taste and then try to put into words.