Stuttering and Stammering

We may also call stammering. In the Diagnostic and statistical manual fifth edition, they call it Childhood-onset fluency disorder:

Repetitions or prolongations of speech sounds OR

1. Hesitations/pauses
2. Marked disturbance in the fluency of speech. 
3. Frequently associated movements, for example:
1. Eye blinks 
2. Tics
3. Tremors of the lips or face
4. Jerking of the head
5. Breathing movements
6. Fist-clenching

These coincide with the stutters. 

Tip > both Stuttering and Stammering include S as in heSitations

Compare this to Staccato Speech