Since I can remember so maybe at 4 years of age. Got over it at like 20. I basically just exposed myself to my worst fears like public speaking, debates, even arguments. I think as someone who stutters, the shame and the insecurity kills ur confidence before u can even try getting over it. I would advice u to be very polite to ur kid because we tend to be very emotional people. Ur kid has a lot of ideas in his head. He wants to say alot of things. He cares about a lot. So when he speaks just listen. Don't smile, just ignore when he/she stutters and let them restart again. The worst thing u can do is make them feel like they are different. But make sure they don't run away from public speaking commitments. The best advice I can give without knowing the specifics of ur child's case is that 1. Tell them to breathe properly. People who stutter tend to find themselves gasping for air and usually because their is so much cortisol running through ur body due to the fear. Slowing ur breath helps in relaxing the body. It's a shift from the sympathetic nervous state to a parasympathetic nervous state. 2. U need to make them understand that in most cases stuttering isn't a defect in the brain or the body. It's more like when u have a lot to say and ur nervous, the body can't keep up with the mind. Slowing ur thoughts, making sure of what ur saying is a way better method. Word by word. It sounds weird at first but then tempo and rhythm tend to gain by themselves. 3. Feeding of my last point. Everyone who speaks has a tempo and rhythm. People who stutters have an underdeveloped tempo and rhythm. I would suggest that u should actually allow ur kid to watch more movies. Humans tend to learn our quirks and behavior through our environment. Many people learn language through media. So if ur kid picks onto something he likes, they tend to imitate it well. Their brains are extremely neuroplastic right now so even a year could be enough to rewire and learn new behaviors. Us older folks will have a harder time though. 4. Lastly, kids tend to be mean. I was bullied for my speech alot. Not being able to speak is like not being able to be yourself. It's not something to scoff at. So being their and showing that u care will make a world of a difference. If u have any specific questions u can DM me and I would love to help. We are organizing a VC in a day or two. We are looking for more members. So if u would like to join, it will be free of cost obviously. But we can always use more people. Thank you. Hope ur kid finds some use from this information.