What are they?

A suffix is a word part placed at the end of a root wood that makes a new word. Suffixes are not words; however, they help to form longer words and can change or add to a word’s meaning. A suffix shows how a word is used in a sentence and what part of speech is formed.

Sometimes adding a suffix to a root word changes the word’s function. Consider the following example:

Example: inject (verb that means to force fluid into a passage)

Example: inject (root word) + ion (suffix) = injection (noun meaning liquid injected into the body with a hypodermic)

Common suffixes

The suffixes “-d/-ed” change the tense of a word. When “-d/-ed” is added to the end of a verb, it changes from the present to past tense. Consider the following examples:

Example 1: live (present tense), lived (past tense)

Example 2: harden (present tense), hardened (past tense)

The suffixes “-s/-es” are used to indicate number. By attaching these suffixes to a singular noun, they turn into plural nouns. Consider the following examples:

Example 1: shoe (singular noun), shoes (plural noun)

Example 2: church (singular noun), churches (plural noun)

The suffix “-ing” changes the tense of all verbs from present tense to present participle (or gerund). Consider the following example:

Example: I heard my neighbor talking on the telephone.

The suffix “-ing” expresses the action of the verb.

Commonly used suffixes

  1. –able and – ible mean capable of, can be done
  2. –al and -ial mean having characteristics of, pertaining to
  3. –en means made of
  4. –er and -est mean comparative
  5. –ful means full of
  6. –ity and -ty mean state of
  7. –less means without
  8. –ness means state of, condition of
  9. –osis means condition
  10. –tude means state of

Spelling rules

Rule #1: When the root word ends with a consonant and the suffix begins with a consonant, combine the root word and consonant with no spelling changes.

Example 1: doubt + ful = doubtful

Example 2: quick + ness = quickness

This holds true even when a prefix is added.

Example 3: dis (prefix) + respect (root word) + ful (suffix) = disrespectful

Rule #2: For one-syllable words that end in a single consonant, double the last letter when you add a suffix.

Example 4: fun + y = funny

Example 5: spin + ing = spinning

Rule #3: For one-syllable words that end with more than one consonant, the last letter is not doubled.

Example 6: jump + ing = jumping

Example 7: ring + ing = ringing

Rule #4: For words pronounced with the emphasis on the last syllable and end with a single consonant, double the last letter.

Example 8: begin + ing = beginning

Example 9: prefer + ed = preferred

Rule #5: For words that are pronounced without emphasis on the last syllable, do not double the last letter.

Example 10: benefit + ing = benefiting

Example 11: offer + ed = offered

Rule #6: If the letter before the final “y” is a consonant, change the “y” to an “i,” and add the suffix.

Example 12: lonely + ness = loneliness

Rule #7: When the first letter in the suffix is a vowel, drop the silent “e.”

Example 13: love + able = lovable

This is true when there is a prefix attached to the word, too.

Example 14: un (prefix) + love (root word) + able (suffix) = unlovable

Common exceptions to rule #7 include acreage, canoeing, hoeing, mileage and singeing.

Rule #8: When the first letter in a suffix is a consonant, keep the silent “e.”

Example 15: care + less = careless

This rule also applies to words with a prefix.

Example 16: un (prefix) + hope (root word) + ful (suffix) = unhopeful