Glossary · Spelling rules and patterns
What is the doubling rule?
Definition
The doubling rule: in a word with one syllable, one short vowel and one final consonant, double that consonant before a vowel suffix, as in hop, hopping.
Teachers often call it the 1-1-1 rule: one syllable, one vowel, one consonant at the end. Run becomes running, big becomes biggest, stop becomes stopped. The doubled letter keeps the vowel short by keeping the syllable closed.
The suffix matters. Only vowel suffixes (-ing, -ed, -er, -est, -y) trigger doubling. Consonant suffixes don't: sad becomes sadly, not saddly. And never double w, x or y (snowing, boxing, playing).
In longer words, double only when the last syllable is stressed: begin becomes beginning, but open becomes opening. That part comes later, once students can hear stress.
In a lesson
Ask the student to add -ing to hop, then hope. Hopping doubles, hoping drops the e. Then try shop and shape. The pairs show why the doubled letter matters for the vowel.
Examples
Each word with its spelling units, one per sound.
- hoppingh·o·pp·i·ng
- stoppeds·t·o·pp·ed
- biggestb·i·gg·e·s·t
- shoppingsh·o·pp·i·ng
- plannedp·l·a·nn·ed
Words come from our lexicon, checked against a pronouncing dictionary. Words a student sees in our assessments are left out.
Why does this matter for the record?
Track doubling with the drop-e rule. Most suffix spelling errors come from mixing the two up, so a rating for each tells you which one to review.
Rate each skill as you teach it
Needs support, Developing, Secure. The rating schedules the review and builds the report.