-ness

-ion, -ment, -ness

These three suffixes are all used to form nouns; -ion and -ment represent Latin elements via Old French and are normally added to verbs to form nouns of action (abridgement, excision) or state (contentment, vexation), whereas -ness is an Old English form, is normally added to adjectives to form nouns of state (bitterness, happiness) or instances of a state or quality (a kindness), and is the most active suffix in forming new words. Regarding -ion and -ment, the choice is largely determined by the forms already existing in Old French, although some nouns were formed on existing English verbs (e.g. acknowledgement, amazement, fulfilment). Some verbs have given rise to more than one form, usually with a difference in meaning (e.g. commission and commitment from commit, excitation and excitement from excite).