spelling: final consonants doubled before a suffix

Follow the guidelines below in deciding whether to double a final consonant before a suffix.

One-syllable words

In a one-syllable word that ends in a single consonant preceded by a single vowel (e.g. bed), double the final consonant before the suffix y or any suffix beginning with a vowel:

• bed: bedded
• dip: dipped
• fat: fatty
• fit: fitted
• flit: flitting
• gum: gummy
• log: logged
• mad: madden
• rot: rotted
• scrub: scrubbing
• sit: sitting
• stop: stopping

Exception: Note that the preferred plural spelling of the noun bus is buses (not busses).

Do not double the final consonant in a word of one syllable if the vowel sound is long:

• boat: boating
• light: lighten
• read: reading
• stoop: stooped

Two-syllable or longer words

In words of more than one syllable ending in a single consonant preceded by a single vowel, the final consonant is doubled if the accent is on the last syllable and the suffix begins with a vowel:

• acquit: acquittal
• commit: committal
• occur: occurrence
• prefer: preferred
• rebel: rebellion
• regret: regretted
• transmit: transmitted

Note that there is no doubling of the consonant in targeted and benefited, since the accent is not on the last syllable in target and benefit.

Also, since the accent is on the last syllable in the verb prefer (preFER), the r is doubled in preferred; but that is not the case with the noun preference, because the accent shifts to the first syllable (PRĔference).