Normal disfluencies vs. Stuttering

Normal disfluencies vs. Stuttering Hello all, I have a question I had been thinking about recently (maybe a SLP can weigh in...). I understand it is not uncommon for people who stutter, as well as fluent speakers, to add intersections ("umm", "uhh") into their speech. How uncommon is it for fluent speakers to have syllable or consonant repetition in their speech? I was just curious if it was a common occurrence or if it was something generally linked to PWS Do fluent speakers have sounds/ letter combinations that give them trouble?