Spelling is tied to pronunciation in many ways. If a syllable is short and stressed; that is, if the short vowel sound is spelled with one letter and not two, double the consonant before adding -ED or -ING. For example, BED has a short vowel spelled with one letter. To speak of bed sheets and blankets, we use the word BEDDING. If a male friend giggles at this, know that his interpretation of the word is a verb, to "bed" a woman, and in every culture there can be found males who boast of bedding women.
On the other hand, if the verb has a short, stressed vowel comprised of two letters, the consonant is not doubled. The verb HEAD is such a verb. In the sport of soccer, HEADING the ball is as important as kicking it.
If a verb already ends in two consonants, as the verb END, never add a third consonant. The correct forms are ENDING and ENDED.
For a little practice, spell the -ED and -ING forms of the words in the following table. Remember that only stressed syllables are affected by this rule. If a final syllable is unstressed, do not double the consonant. Use the dictionary to type in the word to hear its stress pattern if necessary. [Open Dictionary to hear words][Close Dictionary] [open new window]