Social influences on language development
Parents and care givers clearly influence vocabulary growth. A child who is surrounded by speech and language all the time usually learns language skills faster. Children who are seldom spoken to or read to usually learn to talk later than other children their age. Talking to and reading to a child will have a big effect on how well they are able to communicate later.
Summary
A four year old with a vocabulary of 1000 words has come on a long journey from the new born baby. It is not surprising that some children struggle. Some may have problems producing speech sounds, some with receptive speech (understanding)and some with expressive speech (speaking). All children develop at their own rate., and it's important to know what to expect as early help can make a big difference.
