Good for you for posting this question. Shows you care and want to help. But unfortunately I don’t think there is much you can do for his stutter. Stuttering is his (and our) battle to fight. Best advice I can give is to try to sympathize with his speech troubles and don’t make light of them. To somebody who doesn’t struggle to talk it may seem like “no big deal” to stutter, but to us it’s a huge deal - like literally what we think about most of the day.