The spelling of "ffenced" may seem odd to some, but it is actually the correct way to spell the word "fenced" using the "double f" rule. In English, when a one-syllable verb ends in a single consonant, followed by a vowel and then another consonant, the final consonant is usually doubled before adding a suffix. This is to indicate that the vowel sound before the double consonant is short. Therefore, "fenced" becomes "ffenced" when the suffix "-ing" is added. (IPA: /ˈfɛnst/)