-ation:
* Action: The process of doing something.
* Adaptation: The process of changing to fit new conditions.
* Celebration: A public expression of happiness.
* Conversation: A spoken exchange of ideas.
* Dedication: The act of committing oneself to a cause.
* Education: The process of learning.
* Explanation: The act of making something clear.
* Formation: The act of creating something.
* Imagination: The ability to form mental images.
* Innovation: The introduction of something new.
* Invitation: A request to attend an event.
* Legislation: The process of making laws.
* Motivation: The reason for doing something.
* Nation: A large community of people.
* Observation: The act of noticing something.
* Organization: A group of people working together.
* Presentation: The act of showing something.
* Relaxation: The state of being at ease.
* Revelation: The act of making something known.
* Situation: The circumstances surrounding something.
* Station: A place where something is located.
* Vacation: A period of time away from work.
-ition:
* Addition: The act of adding something.
* Condition: The state of something.
* Definition: The meaning of a word.
* Edition: A version of a publication.
* Exhibition: A public display of something.
* Position: The place where something is located.
* Tradition: A custom or belief passed down through generations.
-sion:
* Admission: The act of allowing someone to enter.
* Collision: The act of two objects hitting each other.
* Conclusion: The end of something.
* Confession: The act of admitting to a wrongdoing.
* Decision: A choice made after consideration.
* Discussion: A conversation about a topic.
* Expansion: The act of making something larger.
* Explosion: A sudden burst of energy.
* Expression: The act of expressing oneself.
* Impression: A feeling or opinion.
* Invasion: The act of entering a place with force.
* Mission: A task or purpose.
* Occasion: A special event.
* Pension: A regular payment made to someone after retirement.
* Permission: The act of allowing someone to do something.
* Profession: A job that requires specialized training.
* Revision: The act of changing something.
* Session: A period of time devoted to a particular activity.
* Suspension: The act of temporarily stopping something.
* Version: A specific form of something.
This list provides a starting point. Many more words ending in -ation, -ition, and -sion exist!