English builds many verbs from nouns and adjectives by adding small endings (suffixes). Modern (adjective) becomes modernise (= make modern). Pure (adjective) becomes purify (= make pure). Short (adjective) becomes shorten (= make short or shorter). Each suffix has a similar core meaning — make something become — but they attach to different kinds of word and produce different verbs. -ise/-ize is the most productive in English; it attaches to many nouns and adjectives. -ify often turns adjectives or short nouns into verbs. -en attaches to short adjectives to make verbs of becoming. Students who know these suffixes can decode unfamiliar verbs in reading and build their own from familiar adjectives. This lesson covers the three main verb-forming suffixes at B1 level and shows how to teach them as productive patterns.
Before you start — think honestly about your own teaching and experience.
Look at the examples. Answer each question before reading the explanation — this is how your students will learn too.
modern (adj) → modernise (= make modern)
private (adj) → privatise (= make private, sell to private owners)
special (adj) → specialise (= become a specialist, focus on one area)
organise (= put in order, plan)
realise (= become aware of, understand)
recognise (= know again, identify)
What does the suffix -ise do? And why is the spelling different in British vs American English?
The suffix -ise (or -ize) attaches mostly to adjectives and some nouns to make verbs meaning make something become or do something. Modern + ise = modernise = make modern. Private + ise = privatise = make private (often used about businesses). Special + ise = specialise = become a specialist. The suffix is highly productive — many new English verbs are made with it. Note the spelling: in British English, both -ise and -ize are used but -ise is more common. In American English, -ize is standard. For a British English resource, students should use -ise: organise, recognise, realise, modernise. The same word with -ize (organize, recognize, realize) is American spelling. Both are correct in their own context, but consistency matters — students should pick one and stick with it.
pure (adj) → purify (= make pure)
simple (adj) → simplify (= make simple)
clear (adj) → clarify (= make clear)
class (n) → classify (= sort into classes)
identify (= work out the identity of)
intensify (= make more intense)
The -ify suffix has a similar meaning to -ise — make something become. How is it different?
Both -ise and -ify mean make something become or do an action. But they attach to different words. -ify often follows short adjectives ending in certain ways: pure → purify, simple → simplify, clear → clarify. The -e at the end of the adjective drops before -ify. -ify also attaches to some short nouns: class → classify (sort into classes). The -ify suffix is less productive than -ise — fewer new English verbs are made with it — but the verbs that do exist with -ify are common and useful. Students often try to apply -ise to roots that should take -ify (purise, simplise — both wrong) or vice versa (modernify — wrong). The choice is fixed by the root, not by a rule, and students must learn each verb as a fixed item.
short (adj) → shorten (= make short or shorter)
wide (adj) → widen (= make wide or wider)
strong (adj) → strengthen (= make strong or stronger)
weak (adj) → weaken (= make weak or weaker)
sharp (adj) → sharpen (= make sharp)
flat (adj) → flatten (= make flat)
soft (adj) → soften (= make soft)
hard (adj) → harden (= make hard)
light (adj) → lighten (= make light)
dark (adj) → darken (= make dark)
The -en suffix attaches mostly to short adjectives. Why does this work for some adjectives but not others?
The -en suffix attaches to short, often single-syllable, adjectives that describe physical or basic qualities — short, wide, strong, weak, sharp, flat, soft, hard, light, dark. The verb means make something become this quality. Shorten = make short or shorter. Widen = make wide or wider. Note that the comparison meaning is built in — shorten can mean make short or make shorter, depending on context. -en does not work with all short adjectives. Big does not become bigen — it stays as enlarge or get bigger. Small does not become smallen — it stays as reduce or shrink. The -en suffix has its own list of verbs and students must learn which adjectives accept it. Spelling: most -en verbs add -en directly without spelling changes (short + en = shorten). A few have small changes: strong + en = strengthen (g + then = gthen), wide + en = widen (just add n).
| Suffix | Attaches to | Makes | Examples |
|---|---|---|---|
| -ise / -ize | Adjectives and nouns (often Latin-origin) | Verb meaning make something become or do an action | modern → modernise, private → privatise, special → specialise, organise, realise, recognise |
| -ify | Short adjectives, some short nouns | Verb meaning make something become | pure → purify, simple → simplify, clear → clarify, class → classify, identify, intensify |
| -en | Short adjectives (often physical qualities) | Verb meaning make something become this quality | short → shorten, wide → widen, strong → strengthen, sharp → sharpen, soft → soften, hard → harden |
| Spelling: -ise vs -ize | Same suffix, two spellings | Both mean the same — choose by region | BRITISH: organise, recognise, realise, modernise | AMERICAN: organize, recognize, realize, modernize |
| Spelling change: drop -e | Adjectives ending in -e drop the -e before -ise/-ify | -e disappears at the join | private + ise → privatise (drop e), simple + ify → simplify (drop e), pure + ify → purify |
| Spelling change: -en additions | Most -en verbs add directly | Some have small changes | short + en = shorten, wide + en = widen, strong + en = strengthen (g + then), light + en = lighten |
| What -en does NOT work with | Some short adjectives do not take -en | Different verbs are used | Big → not biggen, use enlarge | Small → not smallen, use reduce / shrink | Tall → not tallen, use grow taller |
PATTERN 1 — -ise/-ize is the most productive: This suffix attaches to many adjectives and nouns to make verbs. Modern → modernise. Private → privatise. Special → specialise. Standard → standardise. The suffix is still productive — new -ise verbs are still being made. British English prefers -ise; American English prefers -ize. Choose one spelling and use it consistently.
PATTERN 2 — -ify with short adjectives: -ify attaches mostly to short adjectives, especially those of Latin origin. Pure → purify. Simple → simplify. Clear → clarify. Note the spelling change: the final -e drops before -ify (pure + ify = purify, not pureify). -ify also attaches to some short nouns: class → classify (sort into classes), beauty → beautify (make beautiful — though this is rare).
PATTERN 3 — -en for physical adjectives: -en attaches to short adjectives describing physical or basic qualities — short, wide, strong, weak, sharp, soft, hard, light, dark. The verb means make this quality. Shorten = make short. Widen = make wider. Sharpen = make sharp. The pattern works for many but not all short adjectives — students must learn which take -en.
PATTERN 4 — Spelling changes at the join: For -ise and -ify, the -e at the end of an adjective drops: private → privatise, simple → simplify, pure → purify. For -en, most adjectives add the suffix directly without change: short → shorten, sharp → sharpen, soft → soften. A few have changes: strong → strengthen, length → lengthen.
PATTERN 5 — Some adjectives do not take any of these: Not every adjective can become a verb through these suffixes. Big does not become bigen or biggify. Small does not become smallen or smallify. For these, English uses different verbs: enlarge (make big), reduce (make small), shrink (become smaller). Students must learn which adjectives have verb forms and which do not.
PATTERN 6 — Decoding unfamiliar verbs: When students meet an unfamiliar verb in reading, they should look for the suffix. -ise/-ize, -ify, or -en at the end suggests a verb made from a familiar root. Globalise = make global. Personify = represent in person form. Strengthen = make strong. Once students recognise the suffix, they can often work out the meaning from the root.
Verb-forming suffixes are an important word-building topic that completes the suffix family. Students who know the noun suffixes (-tion, -ment, -ity), the adjective suffixes (-ful, -less, -ous, -al, -ive), and now the verb suffixes (-ise, -ify, -en) have a complete picture of how English builds words across parts of speech. This is enormously useful for both reading and writing. A student who reads modernise can decode it from modern + ise. A student who needs a verb from clear can build clarify. The investment in learning these patterns pays off across the rest of the student's English study. Spelling matters: British English -ise should be consistent across a student's writing.
Build a word-family wall showing how the same root takes different suffixes for different parts of speech. Modern (adjective) → modernise (verb) → modernisation (noun). Pure (adjective) → purify (verb) → purification (noun) → purity (noun). The wall shows that suffix patterns work as a system — and that mastering one suffix family helps with all of them.
Complete each sentence with the correct verb form built from the word in brackets.
Each sentence has the wrong verb form. Find the error, write the correct verb, and explain.
Use this sequence directly in class — guided discovery, no textbook needed. Tap each step to mark it done.
STEP 1 — Building verbs from adjectives (5 min): Write modern on the board. Then add modernise. Show that the suffix -ise turns the adjective into a verb meaning make modern. Repeat with two more: pure → purify, short → shorten. Establish that English has three main verb-forming suffixes — -ise, -ify, and -en — each with a similar core meaning.
STEP 2 — The three suffixes and their patterns (8 min): Introduce each suffix with examples. -ISE/-IZE: modern → modernise, private → privatise, special → specialise, organise, recognise. -IFY: pure → purify, simple → simplify, clear → clarify, classify, identify. -EN: short → shorten, wide → widen, strong → strengthen, sharp → sharpen, soft → soften. Drill the patterns until students see them.
STEP 3 — Spelling rules (5 min): Show the spelling changes. -ise/-ify: drop the final -e from the adjective (private → privatise, simple → simplify, pure → purify). -en: usually add directly (short → shorten, sharp → sharpen). Some -en verbs have small changes (strong → strengthen, length → lengthen). Drill the most useful spellings.
STEP 4 — Match the suffix to the root (6 min): Write five roots on the board: modern, simple, sharp, special, strong. Ask students to add the right suffix and produce the verb: modernise, simplify, sharpen, specialise, strengthen. Discuss why each root takes the suffix it does. The choice is not predictable — students must learn each verb.
STEP 5 — British vs American spelling (3 min): Explain the -ise vs -ize spelling. British English uses -ise more often (organise, recognise, realise). American English uses -ize (organize, recognize, realize). For consistency, students should choose one and use it throughout their writing. For a British English resource, -ise is the standard.
Use directly in class — copy, adapt, or read aloud. No printing needed.
For each strategy, choose the option that best describes where you are now.
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