Home / English / Word Study / Suffixes -tion and -sion: Action, Decision and Division
Word Study · Suffixes and spelling
Suffixes -tion and -sion: Action, Decision and Division
Learn how -tion and -sion turn verbs into nouns, use the base verb to choose the right spelling, and practise action, decision, pollution and permission.
The idea
The endings -tion and -sion both usually sound like shun, but they are spelled differently. Both turn a verb into a noun: act becomes action, and decide becomes decision.
The base verb is your clue. If the verb ends in t or ct, add -ion: act + ion = action, collect + ion = collection, invent + ion = invention, subtract + ion = subtraction. If the verb ends in e after t, drop the e and add -ion: celebrate becomes celebration, and pollute becomes pollution.
If the verb ends in d, de or se, the noun often ends in -sion: decide becomes decision, divide becomes division, explode becomes explosion and confuse becomes confusion. If the verb ends in ss, just add -ion: discuss becomes discussion and express becomes expression.
A few words change in a special way. Permit becomes permission, with the t changing to ss. Say the base verb out loud, spell it, then add the ending. A final check: does the noun still look like the verb?
In decision, division, explosion and confusion, the -sion sounds like zhun rather than shun. Both sounds appear in English, so use the base verb for spelling.
Word bank
action
noun · AK-shunsomething that you do; from act + ion
Example: His quick action stopped the spill.
collection
noun · kuh-LEK-shuna group of things gathered together; from collect + ion
Example: She has a collection of hockey cards.
invention
noun · in-VEN-shuna new thing that someone makes; from invent + ion
Example: The telephone was an important invention.
education
noun · ej-uh-KAY-shunlearning at school and from experience; from educate (drop the e) + ion
Example: Education helps us learn new skills.
direction
noun · duh-REK-shunthe way something is going; from direct + ion
Example: Which direction is the library?
subtraction
noun · sub-TRAK-shuntaking one number away from another; from subtract + ion
Example: Subtraction is the opposite of addition.
celebration
noun · sel-uh-BRAY-shuna party or event for a special day; from celebrate (drop the e) + ion
Example: The class had a celebration for the last day.
pollution
noun · puh-LOO-shunharmful stuff in the air, water or ground; from pollute (drop the e) + ion
Example: Pollution can hurt fish in a river.
decision
noun · dih-SIZH-una choice you make; from decide (de becomes s) + ion
Example: It was a hard decision.
division
noun · dih-VIZH-unsplitting a number into equal groups; from divide (de becomes s) + ion
Example: Division shares 12 into 3 groups of 4.
explosion
noun · ik-SPLOH-zhuna sudden, loud burst; from explode (de becomes s) + ion
Example: The fireworks ended with a loud explosion.
confusion
noun · kun-FYOO-zhuna feeling of not understanding; from confuse (drop the e) + ion
Example: There was confusion about the room number.
conclusion
noun · kun-KLOO-zhunthe end of something, or what you decide at the end; from conclude (de becomes s) + ion
Example: Write a conclusion for your paragraph.
discussion
noun · dih-SKUSH-una talk about a topic; from discuss + ion
Example: We had a discussion about recycling.
permission
noun · per-MISH-unbeing allowed to do something; from permit (t becomes ss) + ion
Example: Ask for permission before you borrow it.
expression
noun · ik-SPRESH-una look on a face, or a way of saying something; from express + ion
Example: She had a happy expression.
Worked examples
Example 1 · Verb ends in t
Make a noun from invent.
- Invent ends in t.
- Add -ion: invent + ion.
invention
Example 2 · Verb ends in e
Make a noun from celebrate.
- Celebrate ends in e after t.
- Drop the e: celebrat.
- Add -ion.
celebration
Example 3 · Verb ends in de
Make a noun from divide.
- Divide ends in de.
- The de becomes s: divis.
- Add -ion.
division
Example 4 · Verb ends in ss
Make a noun from discuss.
- Discuss already ends in ss.
- Add -ion.
discussion
Example 5 · Special change
Make a noun from permit.
- Permit ends in t, but the t changes to ss.
- permiss + ion.
permission
Example 6 · Find the base
What verb is conclusion built from?
- Take off -ion: conclus.
- Change the s back to de: conclude.
conclude
Common mistakes
Why this fails: Collect, act and invent end in t, so the nouns are collection, action and invention, not collecsion, acsion or invension.
Why this fails: Decide and divide give decision and division, not decition or divition.
Why this fails: Celebrate + ion is celebration, not celebrateion.
Why this fails: Action and mission both end with a shun sound but use different spellings. Use the base verb.
Why this fails: Discuss already has ss. Add -ion and keep both s letters.
Why this fails: Permit changes the t to ss: permission.
Foundation
Foundation practice
Choose the ending from the base verb.
1. Which spelling is correct for the noun from the verb collect?
- collecsion
- collectsion
- colletion
- collection
2. Which spelling is correct for the noun from the verb act?
- action
- acsion
- actsion
- aktion
3. Which spelling is correct for the noun from the verb decide?
- decition
- decidtion
- decision
- decison
4. Which word is spelled correctly?
- divition
- divistion
- division
- divizion
5. Which is the correct noun for the verb invent?
- invention
- invension
- inventsion
- invenion
6. Which ending goes with the verb educate?
- -sion: educasion
- -tion added to the whole word: educatetion
- -ation: educatation
- -ion after dropping the e: education
7. What is the verb base of the word confusion?
- confus
- confuse
- confusion
- fuse
8. How do the endings -tion in action and -sion in mission usually sound?
- tee-on
- shun
- zee-on
- see-on
Practice
Practice practice
Spell nouns and use them in sentences.
9. Which spelling is correct for the noun from the verb explode?
- explotion
- explodtion
- explojion
- explosion
10. Which spelling is correct for the noun from the verb discuss?
- discussion
- discusion
- discution
- discustion
11. Which spelling is correct for the noun from the verb permit?
- permittion
- permition
- permission
- permishon
12. Which spelling is correct for the noun from the verb celebrate?
- celebrasion
- celebratsion
- celebration
- celebrateion
13. Which spelling is correct for the noun from the verb pollute?
- pollution
- polusion
- pollusion
- polution
14. Which spelling is correct for the noun from the verb subtract?
- subtracsion
- subtractsion
- subtrasion
- subtraction
15. “The teacher said we need ___ to leave the room.”
- division
- permission
- pollution
- action
16. “Write a ___ to end your paragraph.”
- collection
- conclusion
- explosion
- invention
17. Which verbs usually take -sion in the noun form?
- verbs that end in t, such as act and invent
- verbs that end in ct, such as subtract
- every verb that ends in a vowel
- verbs that end in d, de or se, such as decide and confuse
Challenge
Challenge practice
Spot mistakes and explain the rule.
18. Which word is spelled wrong?
- collecsion
- education
- direction
- invention
19. Which word is spelled wrong?
- celebration
- conclusion
- pollusion
- discussion
20. Which verb does the noun explosion come from?
- explose
- explot
- explode
- exploit
21. Which pair matches the verb and its noun?
- divide / division
- act / acsion
- educate / educatation
- permit / permition
22. Which sentence uses the correct word?
- The teacher made a decition after the class discussion.
- The teacher made a decision after the class discusion.
- The teacher made a decison after the class discution.
- The teacher made a decision after the class discussion.
23. Why is permission spelled with ss when the verb is permit?
- The verb ends in e.
- The t changes to ss before -ion.
- Every -sion word has a double s.
- It is a homophone.
24. What is a good strategy for spelling a long -tion or -sion word?
- Spell it the way it sounds.
- Find the base verb first, then add the ending.
- Always pick -tion.
- Always pick -sion.
25. Which word names a choice you make after thinking?
- division
- direction
- discussion
- decision
Answer key
- 1. collection
Collect ends in the letter t, so we add -ion to make collection. The -sion ending is for verbs that end in d, de, se or ss, so collecsion is wrong. The other choices drop a letter that belongs to the base word. - 2. action
Act ends in the letter t, so add -ion: act + ion = action. Acsion and actsion use the wrong ending. Aktion changes the base word. - 3. decision
Decide ends in de, and for many such verbs the de becomes s: decis + ion = decision. Decition uses -tion where -sion is needed. Decidtion keeps the d and adds tion, and decison drops an i. - 4. division
Divide becomes division in the same way as decide becomes decision: de turns into s, then add -ion. The z in divizion is a sound, not a spelling. - 5. invention
Invent ends in t, so we add -ion: invention. Invension uses -sion, which is for d, de, se or ss, and invenion drops the t. - 6. -ion after dropping the e: education
Educate ends in an e, so drop the e and add -ion, which gives education. The letters -ate become -ation in the noun. - 7. confuse
Confusion comes from confuse: drop the e and add -ion. Confus is only part of the word, confusion is the noun itself, and fuse is a different word. - 8. shun
Both endings usually say shun, which is why they are easy to mix up. Spelling must be learned from the base verb. - 9. explosion
Explode ends in de, so de becomes s and we add -ion: explosion. Explotion changes the d to t, which is the -tion pattern, but that pattern is for t, te and ct. - 10. discussion
Discuss already ends in ss, so just add -ion: discussion. Discusion drops an s and the other choices use the wrong ending. - 11. permission
Permit changes the t to ss before -ion: permission. Permittion and permition keep the t, and permishon spells the sound instead of the word. - 12. celebration
Celebrate ends in e, so drop the e and add -ion: celebrat + ion = celebration. The -sion choices use the wrong ending. - 13. pollution
Pollute ends in e, so drop the e and add -ion: pollut + ion = pollution. The -sion choices use the wrong ending, and polution has only one l. - 14. subtraction
Subtract ends in ct, so add -ion: subtraction. The -sion spellings are not used after ct. - 15. permission
Permission means being allowed. Division means splitting, pollution means harmful stuff and action means doing. - 16. conclusion
A conclusion ends a paragraph. A collection is a group of things, an explosion is a loud burst and an invention is a new creation. - 17. verbs that end in d, de or se, such as decide and confuse
Verbs ending in d, de or se often lead to -sion nouns. Verbs ending in t or ct take -tion, and the final-vowel statement is too general to be true. - 18. collecsion
Collect ends in t, so the noun is collection, not collecsion. The other three words are spelled correctly. - 19. pollusion
Pollute ends in e, so the noun is pollution. The other words are correct. - 20. explode
Explosion comes from explode: de becomes s, then add -ion. Explose and explot are not words, and exploit is a different word with a different meaning. - 21. divide / division
Divide becomes division. Act becomes action, educate becomes education and permit becomes permission. - 22. The teacher made a decision after the class discussion.
Decision and discussion are both spelled correctly in the first sentence. The other sentences each include a wrong spelling. - 23. The t changes to ss before -ion.
Permit is an exception to the simple rule: the t becomes ss. Not every -sion word has a double s, since decision has only one. - 24. Find the base verb first, then add the ending.
The ending sounds the same, so sound alone cannot decide. The base verb gives the clue. Always choosing one ending would be wrong half the time. - 25. decision
A decision is a choice. Division is splitting, direction is the way something goes and a discussion is a talk. All four look alike because they start with d and end with -ion.