Theorie:
We can make adjectives from nouns or verbs with the suffixes: -ful; -less; -ive; -ing; -ian and others.
Be careful! Sometimes the spelling changes when you add a suffix.
Here are some of the possible suffixes:
Suffix | Examples |
-able, -ible | admissible, possible, probable, reasonable |
-al | global, final, special |
-ant | resistant, resultant |
-ar | perpendicular, popular, regular, similar |
-ed | interested, limited, related |
-ful | harmful, useful, successful |
-ic, -ical | atomic, basic, mathematic(al), economic(al) |
-ive | active, illustrative, indicative, sensitive |
-less | harmless, helpless, hopeless |
-ory | introductory, preparatory, satisfactory |
-ous | porous, serious, various |
-y | busy, easy, early, happy, healthy |
-ing | interesting, depressing, exciting |
Suffixes often change the meaning of the word:
 |  |
This kitten is harmless | This cat is harmful |