Clear English - Strange Spelling and Pronunciation Items - Page 7
Word Endings TION and SION
  1. I found 2191 words ending in TION: Such as abbreviation, addition, calculation, devotion, exception, graduation, insertion, location, medication, notation, partition, question, reception, suggestion, vocation, and others. Generally those words whose roots end in a T or TE will result in TION.
  2. I found 293 words ending in SION: Such as adhesion, cohesion, compassion, convulsion, delusion, intension, torsion and others. Generally those words that end to end with a S or SE will end up with SION.