-ing:
* Running: (run + ing)
* Swimming: (swim + ing)
* Bubbling: (bubble + ing)
* Dropping: (drop + ing)
* Wobbling: (wobble + ing)
-ed:
* Stopped: (stop + ed)
* Planned: (plan + ed)
* Slipped: (slip + ed)
* Happened: (happen + ed)
* Shuffled: (shuffle + ed)
-er:
* Runner: (run + er)
* Swimmer: (swim + er)
* Dribbler: (dribble + er)
* Scribbler: (scribble + er)
* Shimmer: (shimmer + er)
-ness:
* Stiffness: (stiff + ness)
* Oddness: (odd + ness)
* Happiness: (happy + ness)
* Sadness: (sad + ness)
* Roughness: (rough + ness)
-ly:
* Slowly: (slow + ly)
* Clearly: (clear + ly)
* Sadly: (sad + ly)
* Really: (real + ly)
* Oddly: (odd + ly)
-ful:
* Wonderful: (wonder + ful)
* Beautiful: (beauty + ful)
* Joyful: (joy + ful)
* Helpful: (help + ful)
* Skillful: (skill + ful)
-less:
* Hopeless: (hope + less)
* Useless: (use + less)
* Pointless: (point + less)
* Sleepless: (sleep + less)
* Homeless: (home + less)
-ment:
* Judgment: (judge + ment)
* Movement: (move + ment)
* Argument: (argue + ment)
* Treatment: (treat + ment)
* Adjustment: (adjust + ment)
Note: This is not an exhaustive list. There are many other words with double consonants and suffixes.