Do you know what your child should be able to understand and say by age 4? Do you know what you can expect from them socially and how to help them grow their overall communications skills?  At this age, you may want to think about letting them take the lead a little bit.  Give them the opportunities to interact and express themselves with others.  You are your child's biggest role model, be the best example of a great communicator as much as you can.  Be aware of the definite red flags at this age to seek professional advice and early intervention if necessary.