prefix A word part, such as pre-, anti-, or bi-, that is attached to the beginning of a word to form another word: preconceived, unbelievable.
suffix A word part, such as -ly, -ment, or -ed, that is added to the end of a word to change the word’s form (bright, brightly) or tense (call, called) or to form another word (govern, government).
Although English has a large number of words with unusual spellings, many follow the patterns that spelling rules describe.
Add a prefix to a root without doubling or dropping letters.
| distrust | misbehave | unable | |
| dissatisfy | misspell | unnatural |
Add a suffix beginning with a vowel (such as -ing) in accord with the form of the root word.
Double the final consonant if the word has a single syllable that ends in a single consonant preceded by a single vowel.
| begging | hidden | fitting |
Do the same if the word has a final stressed syllable that ends in a single consonant preceded by a single vowel.
| beginning | occurrence |
The final consonant does not double if the word ends in a double consonant or has a double vowel.
| acting | parted | seeming | stooped |
In some cases, the stress shifts to the first syllable when a suffix is added. When it does, do not double the final consonant.
| prefér: | preférring, | preférred | |
| préference, | préferable |
Add a suffix that begins with y or a vowel by dropping a final silent e.
| achieving | icy | location | |
| grievance | lovable | continual |
Keep the final silent e to retain a soft c or g sound, to prevent mispronunciation, or to prevent confusion with other words.
| changeable | courageous | noticeable | |
| eyeing | mileage | canoeist | |
| dyeing | singeing |
Add a suffix that begins with a consonant by keeping a final silent e.
| achievement | discouragement | sincerely |
Exceptions: acknowledgment, argument, awful, judgment, truly, wholly
Form the plural of a singular noun in accord with its form.
If a singular noun ends in a consonant followed by y, change y to i and add -es.
| baby, babies | cry, cries |
Note: Simply add -s to names: her cousin Mary, both Marys.
If a singular noun ends in a vowel followed by y, add -s.
| trolley, trolleys | day, days |
If a singular noun ends in a consonant and o, add -es.
| potato, potatoes | echo, echoes | veto, vetoes |
Exceptions: autos, dynamos, pianos, sopranos
If a singular noun ends in a vowel and o, add -s.
| video, videos | rodeo, rodeos | radio, radios |
If a singular noun ends in s, ss, sh, ch, x, or z, add -es.
| Jones, Joneses | hiss, hisses | bush, bushes |
| match, matches | suffix, suffixes | buzz, buzzes |
Note: The plural of thesis is theses.
Check the dictionary for the plural of a word that originates in another language.
| criterion, criteria |
| datum, data |
| medium, mediums or media |
| hors d’oeuvre, hors d’oeuvres or hors d’oeuvre |