Do other prefixes absorb too?

Yes: ad- becomes ac-, af-, ap- (accept, affect, appear), and com- becomes col-, cor-. The in- family taught here is the clearest doorway into the whole phenomenon.

How does this help with meaning?

Most words on the page mean not-something. A reader who spots absorbed in- instantly negates the base: irresponsible, not responsible. It is speed-reading for meaning.

6th grade absorbed prefixes (im-, il-, ir-)

6th grade absorbed prefixes (im-, il-, ir-) worksheets

Sixth graders read and spell absorbed-prefix words confidently, explain the double letters at the seam, and extend the idea to other absorbing prefixes they meet (ad-, com-).

Free printable PDF worksheet, aligned to Common Core L.6.4.b.

Each print is a different sheet with its own answer key. You don't need to sign up.

The kind of words you'll complete and sort

Fill in the missing letters to make a real word, then write the whole word in its column.

legiblepartiallusionreplaceablerationalperfectresistiblemobilelogical

Columns: im- and il- and ir-. Only im turns "_partial" into a real word, so impartial goes under im-; Only il turns "_logical" into a real word, so illogical goes under il-; Only ir turns "_resistible" into a real word, so irresistible goes under ir-.

Every print pulls a new set of words at this level, so a make-up test or a second sibling gets a different mix.

What's on a 6th grade sheet

6th grade sheets draw from 24 words, 21 to a page. 5th and 6th grade print from the same 24 words. What changes is the standard (L.6.4.b here) and the teaching notes below.

Some of the words:

impatientimmobileimbalanceimmortalillegibleilliterateirregularirrationalirreplaceableirreversible

Complete and sort. Fill in the missing letters to make a real word, then write the whole word in its column. 21 words per page.

Every version prints on US Letter or A4, with its answer key on the last page.

How to teach this

Ask WHY the prefix changes: have your child try saying 'inpossible' and 'inlegal' quickly. The mouth smooths them automatically, which is exactly what happened to the language. Rules the mouth explains are never forgotten.

Watch for: All three prefixes are the same prefix, in-, wearing camouflage. Only the spelling changes to match the next letter; the meaning rides along untouched. The absorption explains the double letters kids find mysterious: illegal has two l's because in+legal fused. Seeing the seam makes the spelling logical instead of random.

Common questions about 6th grade absorbed prefixes (im-, il-, ir-)

Do other prefixes absorb too?: Yes: ad- becomes ac-, af-, ap- (accept, affect, appear), and com- becomes col-, cor-. The in- family taught here is the clearest doorway into the whole phenomenon.
How does this help with meaning?: Most words on the page mean not-something. A reader who spots absorbed in- instantly negates the base: irresponsible, not responsible. It is speed-reading for meaning.

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Aligned to Common Core L.6.4.b. Reviewed by the One more sheet team. Content version 241, updated August 2026.

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