Suffixes
A suffix is a letter or group of letters added at the end of a word which makes a new word. The new word is most often a different word class from the original word. In the table below, the suffix -ful has changed verbs to adjectives, -ment, and -ion have changed verbs to nouns. If you see a word ending in -ment, for example, it is likely to be a noun (e.g. commitment, contentment).
Words forget, use
Suffix -ful
New Words forgetful, useful
Word Class → Word Class verb → adjective
Words state, govern
Suffix -ment
New Words statement, government
Word Class → Word Class noun → collective noun