I'd be patient a little longer. A language explosion should be in right around the corner. By 18 months, he should have 10 to 20 words. Those words may not sound anything like the words you use and know however: He will drop sounds out of the word, use different sounds for ones he can't say yet, or even just make up his own word. If you know what he means when he says something, not matter how odd the word sounds, then it's a word. By the time he is 7 (yes 7) he will have clear speech.
If he doesn't have 10 to 20 words by 18 months have him evaluated. He may be just fine and more time will help (that's probably what your doctor will say) or there may be a problem. At 18 months, let a speech specialist evaluate him if you are still concerned.
at 11:43 AM on Jun. 22, 2009