Advice on how to prevent children from being sloppy speakers and to help them distinguish between language suitable for the nightclub and the job interview has been sent to teachers.
The 60-page guide for secondary teachers, published by the Qualifications and Curriculum Authority, advises on grammar and sentence structure and contains tips for class discussions.
There is also a section on the acceptability of dialect or slang.
Introducing the Grammar of Talk includes such technicalities as deixis, which describes orientational features of language such as "Could we just move that into this corner there?" and ellipsis, when subjects and verbs are omitted, such as "Sounds good to me", where "it" or "that" is left out.
The guide, by Ron Carter, professor of modern English language at Nottingham university, has been tried out in 30 schools.
He said the aim was to show how spoken language should be used in different situations. "It is difficult to divorce speech from writing, and children often find it difficult to make the transition from how they speak and how they write," said Professor Carter.
Children are already taught speaking and listening skills as part of the national curriculum, though schools tend to focus on reading and writing.
Sue Horner, lead consultant for English at the QCA, said: "All young people must be able to express themselves in a comprehensible way, appropriate to the audience they are talking to, if they are to take on the opportunities and responsibilities of adult life."
Last year David Bell, the chief inspector of schools, said that half of four and five-year-olds in 350 schools visited by inspectors lacked basic speaking and listening skills because of their "disrupted and dishevelled" lives.
Gary Snapper, of the National Association for the Teaching of English, said: "Anything associated with the work of Professor Carter is bound to be a useful resource for teachers in the classroom. The teaching of spoken English can be a very sensitive and complex issue but it is something that must be taught."
Dr Neil Gilroy-Scott, director of education for the English Speaking Union, said: "Unfortunately we have many teachers who do not have a grounding in grammar themselves, and they need to feel confident when asked to explain how language works."
Introducing the Grammar of Talk is available from QCA publications on 08700 606015 (ref: QCA041291), or can be downloaded at www.qca.org.ukages3-14subjects9431
LANGUAGE CLASS TIPS
* Give pupils (at Year 10) a series of pictures of Little Red Riding Hood, Cinderella or another well-known story. Ask them to discuss the main features of these stories. Explain that in the past these tales would have been told, rather than read, by skilful storytellers. Ask how an oral story would differ from a written one.
* Ask pupils in pairs to think of the structure of a traditional story, such as Sleeping Beauty or The Three Little Pigs. Tell them to arrange them into five chronological steps in brief note form. Let them take turns to be storyteller and listener. The listener should assess the performance of the storyteller.