This might help someone learn the four circular shapes used for the 4 vowel sounds IH AH EH and UH.

Using your index finger of your writing hand, trace in the air small circles (clockwise) and large circles (also clockwise). When making a small circle say out loud "in" (IHN) once each loop. When making a large circle say out loud "on" (AHN).

Similarly for the counterclockwise motions: Trace a small circle counterclockwise and say "CEN-ter" (SEHN-TR). Trace a large circle (counter-clockwise), say outloud "SUN" (SUHN).

Gradually change saying "In" to IH and "On" to AH. Likewise, change saying "Center" to EH and Sun to UH

-- doug edmunds