Free printables for teaching the 1-1-1 Rule: Doubling Rule worksheet and poster for literacy education.

Let’s go step by step to solve the “Doubling Rule Practice” worksheet.

We are using the 1-1-1 Rule:
> When adding a vowel suffix (like -ed, -ing, -er, -es), double the final consonant only if the base word has:
> ✔ 1 syllable
> ✔ 1 short vowel
> ✔ 1 consonant at the end

If all three are true → double the last letter before adding the suffix.
If any one is false → do NOT double.

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Let’s check each row:

1. plug + -ed

- Syllables: 1 ✔️
- Short vowel? “u” in plug = short u ✔️
- Ends with 1 consonant? “g” ✔️
→ Double the g → plugged ✔ (already done)

2. swim + -er

- Syllables: 1 ✔️
- Short vowel? “i” in swim = short i ✔️
- Ends with 1 consonant? “m” ✔️
→ Double the m → swimmer

3. bend + -ing

- Syllables: 1 ✔️
- Short vowel? “e” in bend = short e ✔️
- Ends with 1 consonant? “d” ✔️
→ Double the d → bending

4. tap + -ed

- Syllables: 1 ✔️
- Short vowel? “a” in tap = short a ✔️
- Ends with 1 consonant? “p” ✔️
→ Double the p → tapped

5. fall + -ing

- Syllables: 1 ✔️
- Short vowel? “a” in fall = short a? Wait — actually, “fall” has a long sound because of the double L already? But let’s think: The rule says “short vowel”. In “fall”, the vowel is followed by two consonants — so it’s not a CVC pattern. Actually, “fall” does NOT have a short vowel sound — it’s more like /ɔ/ or /ɑː/. Also, note: the base word ends with TWO consonants (“ll”) — so it fails the “1 consonant at the end” rule.
→ Does NOT meet 1-1-1 → Do NOT double → falling

Wait — correction: The rule says “ends with 1 consonant”. “fall” ends with “ll” — that’s two letters, but they’re the same consonant. However, for the doubling rule, we care about whether the *last letter* is a single consonant after a short vowel in a 1-syllable word. Since “fall” already has double L, and the vowel isn’t really short in the CVC sense, we don’t add another L. So: falling

Actually, standard answer: “fall” + “ing” = falling — no extra doubling needed because the base word doesn’t fit 1-1-1 perfectly (vowel isn’t short in the required way, and ends with double consonant). So we just add -ing.

But let’s be precise: The 1-1-1 rule applies when you have a 1-syllable word ending in 1 consonant, preceded by 1 short vowel. “Fall” ends in 2 consonants (even though same letter), so it doesn’t qualify. → falling

6. plan + -er

- Syllables: 1 ✔️
- Short vowel? “a” in plan = short a ✔️
- Ends with 1 consonant? “n” ✔️
→ Double the n → planner

7. grip + -ing

- Syllables: 1 ✔️
- Short vowel? “i” in grip = short i ✔️
- Ends with 1 consonant? “p” ✔️
→ Double the p → gripping

8. miss + -es

- Syllables: 1 ✔️
- Short vowel? “i” in miss = short i ✔️
- Ends with 1 consonant? “ss” — that’s two consonants! So fails the “1 consonant at the end” rule.
→ Do NOT double → misses

Note: Even though “miss” ends with ‘s’, it’s doubled already. We don’t triple it. Just add -es → misses.

9. jog + -er

- Syllables: 1 ✔️
- Short vowel? “o” in jog = short o ✔️
- Ends with 1 consonant? “g” ✔️
→ Double the g → jogger

10. leap + -ing

- Syllables: 1 ✔️
- Short vowel? “ea” in leap = long e sound ✘ (not short!)
→ Fails short vowel condition → Do NOT double → leaping

11. invest + -er

- Syllables: in-vest → 2 syllables ✘
→ Fails 1 syllable rule → Do NOT double → investor

12. iron + -ing

- Syllables: i-ron → 2 syllables ✘
→ Do NOT double → ironing

Also, “iron” ends with “n”, but vowel is not short? Doesn’t matter — already failed syllable count.

13. end + -ing

- Syllables: 1 ✔️
- Short vowel? “e” in end = short e ✔️
- Ends with 1 consonant? “d” ✔️
→ Double the d → ending

14. pat + -ing

- Syllables: 1 ✔️
- Short vowel? “a” in pat = short a ✔️
- Ends with 1 consonant? “t” ✔️
→ Double the t → patting

15. keep + -er

- Syllables: 1 ✔️
- Short vowel? “ee” in keep = long e ✘
→ Do NOT double → keeper

16. kick + -ed

- Syllables: 1 ✔️
- Short vowel? “i” in kick = short i ✔️
- Ends with 1 consonant? “ck” — that’s two consonants! So fails “1 consonant at the end” rule.
→ Do NOT double → kicked

Even though “kick” sounds like it might need doubling, the rule requires exactly 1 consonant at the end. “ck” counts as two letters/consonants. So we just add -ed → kicked.

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Now, let’s fill in the table correctly:

| Base Word | Suffix | 1 Syllable | 1 Short Vowel | 1 Consonant at end | Rewrite Base + Suffix |
|-----------|--------|------------|---------------|---------------------|------------------------|
| plug | -ed | ✓ | ✓ | ✓ | plugged |
| swim | -er | ✓ | ✓ | ✓ | swimmer |
| bend | -ing | ✓ | ✓ | ✓ | bending |
| tap | -ed | ✓ | ✓ | ✓ | tapped |
| fall | -ing | ✓ | ✗ (or ambiguous) | ✗ (ends with ll) | falling |
| plan | -er | ✓ | ✓ | ✓ | planner |
| grip | -ing | ✓ | ✓ | ✓ | gripping |
| miss | -es | ✓ | ✓ | ✗ (ends with ss) | misses |
| jog | -er | ✓ | ✓ | ✓ | jogger |
| leap | -ing | ✓ | ✗ (long e) | ✓ | leaping |
| invest | -er | ✗ (2 syl) | ? | ? | investor |
| iron | -ing | ✗ (2 syl) | ? | ? | ironing |
| end | -ing | ✓ | ✓ | ✓ | ending |
| pat | -ing | ✓ | ✓ | ✓ | patting |
| keep | -er | ✓ | ✗ (long ee) | ✓ | keeper |
| kick | -ed | ✓ | ✓ | ✗ (ends with ck) | kicked |

For the checkmarks in columns 3–5, we mark only if the condition is met.

Final filled answers for “Rewrite Base + Suffix” column:

1. plugged (given)
2. swimmer
3. bending
4. tapped
5. falling
6. planner
7. gripping
8. misses
9. jogger
10. leaping
11. investor
12. ironing
13. ending
14. patting
15. keeper
16. kicked

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Final Answer:
swimmer, bending, tapped, falling, planner, gripping, misses, jogger, leaping, investor, ironing, ending, patting, keeper, kicked