The number of five and six year olds who need speech and language support at school has risen by 10% in England over the past year, BBC analysis shows.
The increase, which is substantially greater than previous years, is partly due to lockdown limiting social interactions, experts say.
The Royal College of Speech and Language Therapists says the profession is struggling to cope with the demand.
The government says it is investing £180m in early years development.
The BBC's Shared Data Unit's analysis found that the number of children in Year 1 who needed help with their language use increased more than most other areas of special educational needs.
