A lack of trained teachers and poor awareness of communication problems are fuelling widespread speech difficulties, according to the new government tsar for language development.
Pupils' problems go undetected because they have limited access to therapy and school staff lack expert knowledge, Jean Gross said.
A National Year of Communication - modelled on 2009's National Year of Reading - is being organised by speaking and listening "champion" Mrs Gross in an effort to tackle the issue.
She has called for urgent action, demanding an increase in the number of specialists working in schools to help children to enjoy better and quicker access to treatment and more training for teachers.
About 10 per cent of pupils have speech and language difficulties, but in some cities this rises to 60-75 per cent among deprived communities because parents do not know how to communicate with their children.
Mrs Gross said she wanted teachers to be better trained at speaking to young children - a "Mind Your Language" campaign will encourage them to be clearer, give shorter instructions and help them to introduce new vocabulary.
Health visitors and speech and language therapists will produce guidance for teachers and parents which shows the communication milestones children should be reaching.
Mrs Gross told The TES that many problems go undetected because school staff are unaware of how children should be speaking.
She added that increasingly poor speaking and listening skills are causing bad behaviour in schools which leads to criminality in later life.
Schools Secretary Ed Balls, who has spoken of his efforts to overcome a lifelong stammer, announced the appointment of Mrs Gross as communications champion last year. Her term continues until next March.
"There's so much focus, rightly, on literacy and numeracy and I want to do the same for oral skills," Mrs Gross said.
"The special educational needs system is not delivering what they need; there needs to be much more access to expert services. There is too much general help and not enough specialism."
Two-thirds of young offenders have communication problems, according to research from the Royal College of Speech and Language Therapists. If issues are addressed earlier fewer children might end up in prison, says Mrs Gross.
"I hope my efforts will lead to more children getting access to speech therapy. If schools pooled budgets to employ specialists they can also plan together and review together. I will be frank, I know this is an uphill struggle in a time of financial difficulties, but I hope to show people they can get better value for money if they work this way," she said.
The aim is to encourage more schools to use their SEN budgets to employ speech therapists. Heads could work together to share their services.
Part of the communication champion's job is to set up local steering groups composed of health workers, parents and teachers, which will improve provision around the country.
Campaigns will also be run encouraging families to talk to each other more.
HOW SOCIAL EXCLUSION AND LACK OF SPEAKING SKILLS GO HAND IN HAND
- Between 50 and 75 per cent of children excluded from school have significant problems with literacy, numeracy and oral language.
- A 2007 Ofsted report found that speaking and listening skills were below the right level in a third of foundation stage classes - mostly those in deprived communities.
- A survey of 200 young people in inner-city secondaries in 2008 found that 75 per cent of them had communication difficulties that hampered relationships, behaviour and learning.
- A Government report on social exclusion in 2007 found those most at risk of communication problems were young offenders, children in care, and those with emotional and behavioural difficulties.
Source: I Can.