I have 3 sons - ages 7, 6 and almost 4. The teachers told me that when my 6 year old was 4 that he needed speech therapy. They were WRONG. I gave him some time, worked with him myself and just had him repeating difficult words over and over....and praised him like crazy when he said them right. They have now said the same thing about my 3 year old. I have other issues with my 3 year old (mild OCD), so he has been to see a psychologist, however, when I asked her about it, she said that he will get it in time. Well, he will be 4 next week and he talks like CRAZY and clearly! Sometimes it takes work, sometimes it takes time. I have since changed preschools and my 3 year old is blossoming. I would suggest you using your own judgement and not taking the word of a preschool teacher. If your pediatrician hasn't suggested it yet, I wouldn't worry about it.