Grade by Grade
B. Foundations of Language · Spelling, Grammar and Punctuation

Chameleon Prefixes: com-, con-, col-, cor-, ad- and en-

B2.1 B2.2About 40 minutes
Learning goals
  • I can explain why some prefixes change their spelling to match the base or root.
  • I can spell words with com-, con-, col- and cor- (with, together).
  • I can spot the prefix ad- (to, toward) hiding in words like attract and affix.
  • I can use en- and em- (to make, to put into) to build verbs.
  • I can use these prefixes to explain double letters in words like collect and correct.

Words to know

prefix
A word part added to the beginning of a base or root that changes its meaning.
assimilated prefix
A prefix whose last letter changes to match the first letter of the root. People also call it a chameleon prefix.
root
The main meaning part of a word. It often can't stand alone, like tract (pull) in attract.
base
A word part that can stand alone as a word, like large in enlarge.
morpheme
The smallest part of a word that has meaning: a base, root, prefix or suffix.

Remember from Grade 4

In Grade 4 you learned that the prefix meaning not changes its spelling: in- (incorrect), im- before b, m, p (impossible), il- before l (illegal) and ir- before r (irregular). That's why illegal and irregular have double letters.

Grade 5 spellers use this idea everywhere. Several other prefixes change too. We call them chameleon prefixes, because like a chameleon lizard changing colour to match where it sits, they change their last letter to match the root.

Why do prefixes change?

Try saying in + possible fast: inpossible. Now say impossible. The second one is easier! Your lips are already closed for the p, so the n turns into m.

Hundreds of years ago, speakers of Latin did this all the time. The spelling changed to match the easier sound, and English kept those spellings. This is great news for spellers: a double letter near the start of a word is often a clue that a prefix is there.

PrefixMeaningSpellingExamples
com-with, togetherbefore b, m, pcombine, compare, compete, commit, community
con-with, togetherbefore most other lettersconnect, construct, contain, conversation
col-with, togetherbefore lcollect, collide, collaborate
cor-with, togetherbefore rcorrect, correspond
ad- and its changesto, towardad- stays, or changes to match: ac-, af-, ap-, at-adjust, admit; accept, affix, approve, attract
en- / em-to make, to put intoem- before b or penlarge, encourage, enable; embed, empower
Chameleon prefixes and their meanings
con-with, togethercom-before b, m, pcombine, comparecon-most lettersconnect, constructcol-before lcollect, collidecor-before rcorrect, correspondSame meaning, different last letter: it changes to match the root.
Like a chameleon changing colour, con- changes its last letter to match the letter after it. The meaning (with, together) stays the same.

The double-letter clue

When the prefix changes to match the root, you often get two of the same letter:

  • col + lect = collect (gather together)
  • cor + rect = correct
  • com + mit = commit
  • at + tract = attract (pull toward)
  • af + fix = affix (fix to something)
  • ap + prove = approve

So when you're spelling a word like collect and wonder one l or two?, think: prefix + root. co- + lect doesn't make sense, but col + lect does. Two l's!

col+lect=collectcor+rect=correctat+tract=attractap+prove=approvethe last letterof the prefix+ the first letterof the root= a double letter
The double-letter clue: when a chameleon prefix matches the root, you get two of the same letter. That's why collect has two l's.
Worked example

Let's spell /uh-TRAKT/

Spell the word that means to pull toward, as in Flowers ______ bees.

  1. Think of the meaning: pull = the root tract (like tractor, which pulls).
  2. Toward = the prefix ad-.
  3. Before t, ad- changes to at-: at + tract.
  4. Put them together. Keep both t's: attract.

attract (a-t-t-r-a-c-t). The double t comes from at + tract.

Worked example

Let's build words with en- and em-

Make verbs that mean to make large, to give courage to, and to put into a bed (to fix something firmly inside something else).

  1. to make large: en + large = enlarge.
  2. to give courage to: en + courage = encourage.
  3. to put into a bed: the base bed starts with b, so use em-: em + bed = embed.

enlarge, encourage, embed. Use em- before b and p.

Just for fun

A chameleon prefix walks up to the word legal. Out walks illegal, wearing an extra l like a brand-new hat.

Root clues for double letters

Correct has two r's because it's cor + rect (rect means straight, as in rectangle). Collect has two l's because it's col + lect (lect means gather or choose, as in select).

Hands-on activity

Prefix detective

You need: paper, a pencil, a highlighter (or coloured pencil), and a newspaper, flyer, cereal box or book.

  1. Make four columns: com-/con-/col-/cor-, ad- family (ad-, ac-, af-, ap-, at-), en-/em-, and in-/im-/il-/ir- (not).
  2. Hunt for words that start with these prefixes. Write each in the right column.
  3. Highlight every double letter you find near the start of a word, like collect or approve.
  4. For each highlighted word, split it into prefix + root and say what the prefix means.
  5. Careful! Not every word that starts with con or en has the prefix (think of cone and end). Check that the word part has a meaning.

Your turn

1

What does the prefix con- (and com-, col-, cor-) mean?

2

Why is combine spelled with com-, not con-?

3

Split collide into prefix + root. Why does it have two l's?

4

Spell the word that means to fix something to something else.

5

Add en- or em-: ___able, ___power, ___danger.

6

Choose the correct spelling: corect or correct?

7

What does construct mean? Use the word parts.

More practice: warm-up

1

What does en- mean in enlarge?

2

Underline the prefix: compare.

3

Underline the prefix: attract.

4

Which prefix is used before l: com- or col-?

5

Add a prefix meaning together: ___nect.

More practice: on your own

1

One m or two? co_unity Explain.

2

Explain the double p in approve.

3

Write a sentence using encourage, and explain the word parts.

4

Your friend wrote colaborate. Fix it and explain.

5

Which word does not have the con- prefix meaning together: connect, construct, cone?

Challenge

1

Explain why immature and illegal have double letters, but inactive doesn't.

2

Accept means to take something that is offered to you. Find the chameleon prefix and explain the double c.

3

Build three words with com-, con-, col- or cor- that could be used in a science report about a volcano project, and explain one.

Check your understanding

Quiz

1.

Why are some prefixes called chameleon prefixes?

2.

Which spelling is correct?

3.

Which prefix goes before b, m and p to mean with, together?

4.

What does attract mean?

5.

Which word uses em- correctly?

6.

Which word has a double letter because of a chameleon prefix?

For parents and teachers

Big idea (B2.1, B2.2): In Grade 5, children use generalized knowledge of morphemes (bases, roots, prefixes and suffixes) to read and spell with accuracy and automaticity. Assimilated (chameleon) prefixes explain many confusing double letters (collect, correct, attract, approve, community). Once a child sees prefix + root, the spelling stops being a mystery.

How to help at home:

  • When your child asks "one letter or two?", ask back: "Is there a prefix? What's the root?"
  • Point out prefixes in everyday words: combine on a recipe, connect on a device, collect in a game.
  • Keep it light. The history (Latin speakers making words easier to say) is a fun story, not a rule to memorize.

Common difficulties:

  • Seeing prefixes that aren't there (cone, enter, comma). Check that the part has a meaning and the rest is a real root.
  • Dropping one of the double letters (colect, acept). Split the word into its parts and write each part.
  • Mixing con- and com-. Look at the next letter: b, m, p → com-.