It is disconcerting when a child first has trouble “getting words out.” You can do things like sing—to help have fun and increase confidence. Do poems, rhythmic activities-things that are fun. For example “Five little monkeys jumping on the bed”. Those are things that support fluency and a positive association with talking. You can model slower speech — and have short pauses between phrases. If YOU slow down the pace it will help slow down every one’s pace. If there are other children be sure he gets his turns to speak without feeling rushed. He’s probably a very bright child that has speech that can’t keep up with all he wants to say. Talking is a balancing act between the skills of thinking of what to say, recalling vocabulary, using correct syntax , and coordinating the lips, tongue, vocal cords and breathing. That’s a lot! Anxiety can play a big role in stuttering. Anyone may stutter if they are nervous. For some the threshold for stuttering is much lower. The more chill you can be about life and his speech the easier it will be for him to be fluent. Best of luck..,,