I started with speech problems basically at speaking age. Stuttering happened a little later (4-5 years old I think). A little note though, a large amount of kids stutter when they're learning to speak. They usually grow out of it. I'm not an expert, but 2 years old seems young to look for a speech therapist. Maybe 4-5 years old when they can actually grasp what's going on in speeh therapy. I wish I'd gotten real speech therapy earlier, but I only started real therapy in my 20s. From what I've read, if you start before the age of 7 or so the chance of success is high. Past the teens it's more about management than anything else.