Word family
The -ill word family
The answer
The -ill word family is every one-syllable word that ends in the rime ill, said /il/. Our lexicon has 23 public words in it: 10 with one consonant first, 10 with a blend, 2 with a digraph or silent-letter pair and 1 with no sound before the rime.
What is in this family?
The ill family is one of the first rimes children hear in rhymes and songs, and it is a good one to teach early. The double l is a spelling students need anyway, because it is the floss rule at work. Every word is one syllable with a short i and ends in ll. Many of its words start with a blend (still, spill, drill, thrill), so the family doubles as blend practice once students read the simple ones.
The words, sorted by what comes before the rime
One consonant before the rime
| Word | Onset + rime | Readable after |
|---|---|---|
| bill | b + ill | Lesson 42 |
| fill | f + ill | Lesson 42 |
| hill | h + ill | Lesson 42 |
| till | t + ill | Lesson 42 |
| will | w + ill | Lesson 42 |
| mill | m + ill | Lesson 42 |
| pill | p + ill | Lesson 42 |
| dill | d + ill | Lesson 42 |
| gill | g + ill | Lesson 42 |
| sill | s + ill | Lesson 42 |
A blend before the rime
| Word | Onset + rime | Readable after |
|---|---|---|
| skill | sk + ill | Lesson 42 |
| still | st + ill | Lesson 42 |
| drill | dr + ill | Lesson 42 |
| spill | sp + ill | Lesson 42 |
| frill | fr + ill | Lesson 42 |
| grill | gr + ill | Lesson 42 |
| swill | sw + ill | Lesson 42 |
| trill | tr + ill | Lesson 42 |
| shrill | shr + ill | Lesson 45 |
| thrill | thr + ill | Lesson 47 |
A digraph or silent-letter pair before the rime
| Word | Onset + rime | Readable after |
|---|---|---|
| chill | ch + ill | Lesson 48 |
| quill | qu + ill | Lesson 42 |
No sound before the rime
| Word | Onset + rime | Readable after |
|---|---|---|
| ill | (none) + ill | Lesson 42 |
Word ladder: change one sound at a time
Every step is a real word from the list, and each one changes exactly one sound. Say the change aloud before the student writes the new word.
| Step | Word | The change |
|---|---|---|
| 1 | ill | start here |
| 2 | bill | add /b/ |
| 3 | fill | change /b/ to /f/ |
| 4 | hill | change /f/ to /hh/ |
| 5 | till | change /hh/ to /t/ |
| 6 | will | change /t/ to /w/ |
| 7 | mill | change /w/ to /m/ |
| 8 | pill | change /m/ to /p/ |
| 9 | spill | add /s/ |
| 10 | skill | change /p/ to /k/ |
Rhymes spelled another way
These words rhyme with the family but spell the rime differently, so they belong to other families. Expect students to mix them up when spelling.
| Spelling | Words |
|---|---|
| -il | nil |
| -ille | grille |
How do you teach it?
Start with onset swaps on a single consonant: bill, pill, mill, till. Then add one sound in front: pill becomes spill, till becomes still. Students hear that the rime never changes; only the start does.
"Our family is i-l-l, /il/. I'll say a sound, you add /il/. /p/: pill. /m/: mill. Now add /s/ in front of pill: spill. What changed? Only the beginning. The /il/ stayed the same."
What is the common error, and the fix?
Students write "bil" or "stil", leaving off the second l. The fix is to connect the family to the floss rule: one syllable, short i, l at the end, so ll.
Sort it: a hands-on activity
Write ill on a strip and keep onset cards in a pile (b, p, m, t, w, sp, st, dr, gr, ch, thr). Students build each word, read it and sort it as real or not real. Then they write the real ones in columns by how many letters come before ill.
How this list was built
Every word comes from our lexicon of about 19,000 common words, each checked against a pronouncing dictionary and split into spelling units. Words a student meets in our assessments and progress-monitoring probes are left out, so practicing a list never rehearses a test. A family is every one-syllable base word (no suffix, not a compound) whose rime, the vowel unit and every unit after it, has the same spelling and the same sounds, so bead and bread are in different families. Ladders use only words from the list, and each step changes exactly one sound.
"Readable after" is the first lesson in the lesson sequence at which our decodability engine finds every sound-spelling in the word taught; "not taught" means the word has a spelling the sequence does not cover, so it is read with help. You can check your own lists and passages with the free decodable text checker.
Questions people ask
How many words are in the -ill family?
Our lexicon has 23 one-syllable words ending in ill that a student can practice. Words used in our assessments are left out, so a few common words may be missing from the list.
Why does every ill word have two l's?
The floss rule: when a one-syllable word has a lone short vowel, its final l is doubled. The ill family is one of the largest floss families.
What is a word ladder?
A chain of real words where each step changes one sound: swap a sound, add one, or take one away. Students say the change before they write it, which trains them to hear every sound in the word.