doubling rule
Core Rule
The consonant doubling rule preserves a short vowel sound when a suffix is added. In a CVC pattern (consonant–vowel–consonant), the final consonant is doubled before -ing, -ed, -er, etc., e.g., run → running.
Pronunciation Guide
Short vowels are brief and tense. Doubling does not lengthen the consonant; it signals vowel quality. The mouth opens quickly and closes without glide.
Word Analysis
thriller: from thrill. The doubled ll locks the /ɪ/ sound, preventing /θraɪlər/. Spelling and sound align systematically.
Pitfalls
No doubling with long vowels (rain → raining), with final w/x/y, or when stress is not on the last syllable (open → opening).
Phonics Breakdown
Produce a quick, tense short vowel; close promptly
Sound Reference
- Check stress before doubling
- Listen for short vowels, not letters
Common Mistakes
Doubling after long vowels
Ignoring stress patterns