Regresing or Regressing: How To spell?
The word Regresing is misspelled against Regressing, which is present continuous of "Regress"
Regressing has double "ss" is mispronounced as "s"Remember double 'SS' in between the strings regre & ing which should not be misspelled with single 'S'
Wrong Spelling:  regre-s-ing  Correct Spelling:  regre-ss-ing 
Find more wrongly spelled words of Regressing to spell it well.