The Suffix -ig
Swedish frequently builds adjectives by adding suffixes to nouns and verbs. The most common is -ig, which functions much like the English suffix "-y" (as in "dirty" or "plasticky"). It describes a quality or characteristic of an object.
The Suffix -lös
The suffix -lös translates directly to the English "-less". It means "without" and is attached to nouns to describe a missing feature. For example, en tråd (a wire) becomes trådlös (wireless), and ett värde (a value) becomes värdelös (worthless).
The Suffix -sam
The suffix -sam indicates that something has a certain tendency or quality. It is similar to the English suffixes "-some" (as in "troublesome") or "-ful" (as in "doubtful"). For example, from the verb tveka (to hesitate), we get the adjective tveksam (doubtful).
Adjective Agreement
Even though these adjectives are built with suffixes, they still follow the standard rules for adjective agreement. When describing an ett-word, you must add -t to the end of the suffix (e.g., -igt, -samt, -löst).
When describing plural nouns, add -a to the end of the suffix (e.g., -iga, -lösa). Note that adjectives ending in -sam double the m in the plural (-samma) to keep the vowel sound short.