B. Foundations of Language · Handwriting, Spelling and Sentences

Suffixes That Build Big Words

B2.1About 40 minutes

Learning goals

I can use the suffixes -ion, -tion, -sion, -ation, -ive, -ous, -ian and -ize to build and understand words.
I can make the spelling changes these suffixes need, like decide → decision.
I can decide whether to double the last consonant in a longer word, like beginning and visiting.
I can spell words in a word family, like create, creation, creative, creator.

Words to know

suffix
A word part added to the end of a base. It can change the meaning or the word's job.

noun
A word that names a person, place, thing or idea.

adjective
A word that describes a noun.

stressed syllable
The syllable you say a little louder and longer, like gin in be-GIN.

Remember from Grade 3

You used suffixes like -ment, -able, -er, -or, -ist, -ful, -less, -ness and -ly. You learned three spelling rules: double the last consonant (hop → hopping), drop the e (bake → baking), and change y to i (happy → happiness).

In Grade 4 you'll learn suffixes that make longer, grown-up words, and you'll use the doubling rule in words with two syllables.

Turning actions into things: -ion

The suffix -ion turns an action word (a verb) into a naming word (a noun). It's often heard as /shun/ or /zhun/.

Base ends in...	What to do	Examples
-t	Just add -ion	act → action, protect → protection, invent → invention
-te	Drop the e, add -ion	create → creation, celebrate → celebration, educate → education
-d or -de	Change to -sion	decide → decision, divide → division, explode → explosion, extend → extension
-se	Drop the e, add -ion	confuse → confusion, revise → revision
Some other words	Add -ation (drop a final e first)	inform → information, invite → invitation, explore → exploration

Choosing -tion, -sion or -ation. These are usual patterns; a few words do something different.

Three ways to add -ion. Letters with a line through them are dropped before the suffix goes on.

Worked example

Let's spell "decision"

Change decide into a noun: It was a hard ______.

The base decide ends in -de.
When the base ends in -d or -de, the noun usually ends in -sion.
Take off the de, add sion: deci + sion.
Say it: /dih-SIZH-un/. The -sion says /zhun/.

decision

More suffixes to know

Suffix	Meaning	Makes a...	Examples
-ive	tends to, has the quality of	describing word (adjective)	active, creative, protective, attractive
-ous	full of, having	describing word (adjective)	dangerous, famous, mysterious, courageous
-ian	a person who does or is from	naming word (noun)	musician, magician, librarian, Canadian
-ize	to make, or to become	action word (verb)	realize, memorize, finalize, organize

Grade 4 suffixes

Spelling changes with these suffixes

Drop the e before a vowel suffix: fame → famous, create → creative.
Change y to i: mystery → mysterious.
Drop the y before -ian: library → librarian.
Keep the e after a soft g before -ous, so the g still says /j/: courage → courageous.
Drop the y before -ize: memory → memorize, apology → apologize.

Doubling in longer words

In Grade 3 you doubled the last letter of short words: run → running. What about longer words like begin and visit? Listen for the stressed syllable (the one you say louder):

be-GIN: the stress is on the last syllable. It ends in one vowel + one consonant. Double: beginning.
VIS-it: the stress is on the first syllable. Don't double: visiting, visited.

Double the last consonant when all three are true:

the suffix starts with a vowel (-ing, -ed, -er),
the word ends in one vowel + one consonant, and
the last syllable is stressed.

The big box is the stressed syllable. Double the last consonant only when the stress is on the last syllable.

Double (stress at the end)	Don't double (stress at the start)
begin → beginning	visit → visiting
forget → forgetting	open → opened
admit → admitted	happen → happened
prefer → preferred	garden → gardener
occur → occurred	limit → limited

Doubling in two-syllable words

A Canadian spelling note

In Canadian spelling, a final l after a single vowel is doubled even when the stress is at the start: travel → travelled, travelling; cancel → cancelled; label → labelled. (In the United States, people often write traveled. In Canada, we write travelled.)

Worked example

Let's add -ing to "forget" and "open"

Spell forget + ing and open + ing.

forget: say it, for-GET. The stress is on the last syllable, and it ends in one vowel + one consonant (e, t). Double the t: forgetting.
open: say it, O-pen. The stress is on the first syllable. Don't double: opening.

forgetting and opening.

Worked example

Let's build a word family

Use suffixes to build words from create.

create + ion → drop the e → creation (a thing that was made).
create + ive → drop the e → creative (good at making new things).
create + or → drop the e → creator (a person who creates).
Each word keeps the base creat-, so if you can spell create, you can spell the whole family.

creation, creative, creator: one base, three suffixes, three jobs.

Just for fun

Why was the word celebrate so happy after it met -ion?

Because now it was a celebration!

Hands-on activity

Suffix building blocks

You need: sticky notes or small paper squares, and a pen.

Write these bases on sticky notes: act, create, decide, danger, music, real, begin, visit.
Write these suffixes on other notes: -ion, -ive, -sion, -ous, -ian, -ize, -ing, -ed.
Stick a base next to a suffix to make a real word, like act + ive. Write the new word underneath, making any spelling change it needs (decide + sion → decision).
Try to make at least 10 real words. (Hint: act can make action and active!)
For each word, say a sentence out loud using it.
Read your list to a grown-up and point out every spelling change you made.

Your turn

Turn act into a noun using -ion.

Turn create into a noun using -ion.

Turn explode into a noun.

Add -ous to danger. What does it mean?

What do you call a person who plays music?

Add -ing to begin.

Add -ed to visit.

More practice: warm-up

What does -ous mean?

What does -ian mean in magician?

Turn protect into a noun.

Add -ize to real.

Which word describes someone full of energy: active or action?

More practice: on your own

Turn divide into a noun. Explain.

Add -ous to fame. Explain.

Add -ing to forget and -ed to happen. Explain each.

How do we spell travel + ed in Canada?

Add -ive to create. Use it in a sentence.

Challenge

Spell mystery + ous, and explain each change.

Spell occur + ed and prefer + ing. Explain why you double.

Build a word family from educate with three suffixes. Tell what each word means.

Check your understanding

Quiz

Which is the noun made from decide?

Which suffix means full of?

Which is spelled correctly?

A person who works in a library is a...

How is travel + ed usually spelled in Canada?

For parents and teachers

Big idea: This lesson extends B2.1 (using morphemes to read and spell) into longer words. Children learn suffixes that change a word's job (-ion nouns, -ive and -ous adjectives, -ize verbs, -ian people) and the stress-based doubling rule for two-syllable words.

How to help at home:

Say long words slowly and exaggerate the stressed syllable: be-GIN, VIS-it. Children often can't hear stress at first; clapping and saying it louder helps.
Build word families together: act, action, active, actor, react.
Point out Canadian spellings in books and newspapers: travelled, colour, centre.

Common difficulties:

-tion vs -sion: look at the base's ending (t/te → -tion; d/de → -sion). These are patterns with some exceptions.
Doubling everything (visitted) or nothing (begining). Go back to the three-part test.
Forgetting to drop the e (createion) or dropping it when it should stay (couragous).
Many spell-checkers are set to US English and will mark travelled or colour. Show your child how to set the language to English (Canada) if possible.