A three year old boy should be speaking a approximately 100 words and if not should be evaluated by a qualified speech pathologist to determine the best course of action.
A typical three year old should have mastered numerous words and how to use them properly. He or she should also be speaking in complete sentences. These sentences should only be four to five words however.
If you think he has a problem see a therapist and have him tested, before he starts school. This is correctable, but should be done early so he won't get teased about it in school.
Three year olds should have on average 50 to 100 words in their voculabary. They should also respond to two word commands and be able to tell you two to three word sentences.
