Just make sure that he never feels like you treat him like he is less capable than his siblings/friends because of his speech. You said you will support him through thick and thin so I have no worries whatsoever about you doing your best for him; however, my parents tried to help me by always talking for me (in restaurants or phone calls etc) and this just meant that I'm now a 17 year old who is terrified to speak. Mainly because I expect the worst reactions. In reality, most people are super nice and accepting, but by always speaking for me, my mum kind of ingrained the idea that people will be mean and that I'm not capable of speaking for myself, if that makes sense? You have to push him to speak, even if he seems like he wants you to do it for him. Make sure he knows that you're by his side, supporting him, but tough love goes a long way here. Eventually his confidence will grow. Also, when he starts school, I think it might be a good idea to talk to his teacher. My stutter isn't that bad so I don't think my teachers ever knew, but this meant that I just never spoke in class in order to keep it hidden. If you discretely tell the teacher at least it's out in the open, and if he answers a question the teacher will know to just give him an extra few seconds rather than thinking he doesn't know what he's saying. Most importantly, I'm sure he is a very clever and sweet boy who will succeed in life whatever he want to do! He clearly has the support of his family and that means everything x