The best technique is to use simple words and straightforward explanations. Give the child time to digest the information and later ask her what she remembers about the discussion. Try not to end sentences or finish phrases. Allow the child his own pace when telling you something or asking a question. Say it again and again.
Most youngsters can only take in so much information at one time.
You will have to repeat yourself until they are able to absorb the message. Give your child your undivided attention. Find the time to talk when you can look your child in the eye and really listen. This adds conviction to your message and makes your child understand that she is worthy of your time. Speak separately to kids of different ages.