New to the sub, looking for advice.

New to the sub, looking for advice. Hey everyone, just found this sub and I've always been interested because my dad has had a stutter his entire life. It's more severe than almost anything I've seen, meaning he can hardly get through a sentence without stuttering. My mom has told me to just have patience, but I thought I'd ask you guys if there is anything else I can do to make conversing with him easier and better for him.