my son will complete 4yrs next week. he is the only child. whenever he plays at home...he is talking to another 'imaginative' child and having a good talkative conversation. do i need to be concerned?

having imaginary friend now is fine but not in the long run. u kight wish to bring him around to socialize, hae interaction with other kids. well, normally the so called friend or friends will suddenly disappear out of a sudden. relax.