Disfluency starts to be noticeable above about 5% of syllables. Below that and you’re considered within normal limits. However, that’s a very listener-focused criteria. I’ll second what someone else said: if you think about it like this, you probably “count.” > can you develop a stutter in your teenage years It’s not unheard of, but it is rare. Typically it develops in early childhood, and if it’s going to resolve, does so within a few years.