Adjective Formation: Common Prefixes and Suffixes

Adjectives are words that describe nouns. We can make adjectives by adding prefixes and suffixes.

Suffixes to form adjectives

Suffixes go on the end of words. They change a word from one part of speech, such as a noun or a verb, to another, such as an adjective.

For example, if you add ‘-able’ to ‘solve’, you create the adjective ‘solvable.  

  • They told me the problem was not solvable, but I thought it was easy.
  • The professional secretary was very helpful. She immediately understood what I needed.

The word ‘professional’ comes from ‘profession’, and ‘helpful’ comes from ‘help’.

The most common adjective suffixes and their meaning:

-able/-ibleWorth, abilitySolvable, accessible, believable, reliable
-al, -ial, -ical Quality, relationProfessional, structural, national, legal
-ent/-antHaving a certain qualityImportant, dependent, relevant
-edHaving the quality of Bored, interested, fascinated
-icQuality, relationGeneric, archaic, idealistic, historic
-ingReferring to an activityBoring, interesting, fascinating
-ishHaving the character of, about, almostNewish, reddish
-fulHaving a characteristicHelpful, colorful, useful
-lessWithout, missingWorthless, careless, useless, hopeless
-ousHaving the quality of, relating toAdventurous, courageous, advantageous
-iveHaving the quality ofFestive, cooperative, sensitive

Thus, suffixes can determine the word’s part of speech. Certain suffixes make the base or root word a noun, a verb, an adjective, or an adverb. For example, if you know suffixes that are typical for adjectives you will easily differentiate the adjectives from other parts of speech or determine the meaning of a word:

  • history (noun) – historic (adjective)
  • hopeful (giving hope) – hopeless (without hope)
Note: Some words can be two parts of speech. This is true for words that end in ‘-ed’ and ‘-ing’, such as ‘bored‘ and ‘boring‘. In the first and third sentences below, the words are verbs, while in the others they are adjectives. In the second sentence, ‘bored describes the person ´I´, and in the last sentence ‘boring describes the word ´subject´.
  • His lecture bored the class so everyone fell asleep.
  • I was so bored in his class that I fell asleep.
  • You are boring me with all this information about insects.
  • This is a very boring subject.

Here’s an interesting video about how to use adjectives with suffixes ‘-ing’ and ‘-ed’ correctly:

Prefixes to form adjectives

Prefixes go at the beginning of words.

The most common adjective prefixes and their meaning:

Prefix Meaning Examples
il-, im-, ir-, in-Not/opposite of Illegal, Illegible, imperfect, impolite, irrelevant, irrational, inconvenient, inactive
un- Not/opposite of Unusual, unhappy, uninterested, unpleasant
dis-Not/opposite ofDishonest, disloyal, dissimilar, disabled
ultra-, super-, -hyper-ExtremeUltra-compact, ultrasound, hyperactive
inter-BetweenInternational, interdisciplinary
trans-AcrossTransatlantic, transmarine
  • I cannot read anything she writes; her writing is illegible.
  • Companies don’t like to work with dishonest employees.  

Spelling rules for il-, im-, ir-, in-

  1. Use ‘il-’ for words starting with ‘l’, such as legal (illegal) and legible (illegible).
  2. Use ‘ir-’ for words starting with ‘r’, such as relevant (irrelevant) and rational (irrational).  
  3. Use ‘im-’ for words starting with ‘m’ or ‘p’, such as mature (immature) and polite (impolite)
  4. For other adjectives, use ‘in-’, such as convenient (inconvenient) and active (inactive).
Note: Not all prefixes can go on all words, so it is important to use your dictionary to help you learn which prefixes are used with which words.

In this video from Shaw English Online, you’ll see how different adjectives are formed using prefixes and suffixes:

Read more on this topic:

How to Form Adverbs

Verb Formation: Common Prefixes and Suffixes

Noun Formation: Common Prefixes

Noun Formation: Common Suffixes

Leave a Comment