As a parent, you have to observe your baby. the response of baby is the best guideline for detecting speech problems. Inability to express may mean that he may be having speech delay or a speech disorder.
Some children are late to start talking. some babies can make themselves understood by using movements and noises instead of using their words. Parents should make sure that younger children are encouraged to talk. Early detection can help in problem solving. If there is a problem don't waste time before helping the child.
Some children do grow out of speech or language problems but it is best not to wait and see. The sooner a problem is discovered the sooner it can be treated. Children often repeat words or phrases when they learn to talk, and many of them will outgrow this.