A speech disorder (speech difficulty) may be due to an inability to articulate particular speech sounds. This is a phonetic disorder. There may also be difficulties in understanding and applying the rules which govern how particular speech sounds can be used in particular words. This is a phonological difficulty. A Stimulability Test can be conducted to rule out any phonetic difficulties.
There are many stuttering problems for people who stutter. People with an established stutter are aware of the negative effect of repetitions, prolongations, hesitations and blocks on their speech. Their stutter (stammer) may be accompanied by facial tics and uncontrolled body movements. Stuttering can lead to the avoidance of certain activities and to social isolation.