ADJECTIVE SUFFIXES


Suffixes change word class, e.g. from verb to noun or noun to adjective, but they can also change meaning.


Noun or verb + suffix


Noun or verb                              Suffix               Adjectives


danger, fame                                -ous                  dangerous, famous
music, politics                              - al                    musical, political
industry, economics                                              industrial, economical
cloud, fog, sun, dirt                      - y                    cloudy, foggy, sunny, dirty
attract, create                               - ive                  attractive, creative

Note:  Sometimes there is a spelling change. Here are common examples:
double the consonant: sun/sunny; fog/foggy
leave out the final "e": create/creative; fame/famous
leave out the final "s" before "-al": politics/political; economics/economical
change "y" to "i" before "-al": industry/industrial




-able


This suffix (also -ible in some words) is used to form many adjectives from nouns or verbs:

enjoyable, comfortable, knowledgeable, suitable


Quite often, -able (and -ible) has the meaning "can be done". For example, something that is washable "can be washed". Other examples include:

drinkable, comprehensible, reliable


Words ending -able quite often express the opposite meaning by adding the prefix un-


undrinkable, unreliable, unbreakable, unsuitable, uncomfortable


Words ending -ible add the prefix in-


incomprehensible, inflexible, inedible




-ful and -less


The suffix -ful often means "full of" + the meaning of the adjective: careful, helpful, painful, useful, thoughtful.


The suffix -less means "without" + the meaning of the adjective: careless, painless, useless, thoughtless, jobless, homeless


Note:  You can see that -ful and -less are often used with the same words to form opposites. This is not always true.


(From the book English Vocabulary in Use - by Stuart Redman - Cambridge University Press