What is a derivational suffix?

A derivational suffix is a type of morpheme that, when added to a base word, creates a new word with a different part of speech or function. This transformation often alters the meaning of the original word significantly. For example, adding the suffix "-er" to the verb "teach" creates the noun "teacher," effectively changing the word from an action (verb) to a person who performs that action (noun). Similarly, adding "-ness" to the adjective "happy" forms the noun "happiness," changing the descriptor into a state or quality.

Understanding the role of derivational suffixes is crucial for grasping how the meaning and grammatical role of words can change in a language. This is in contrast to inflectional suffixes, which modify a word for tense, case, or number without changing its part of speech. The emphasis of derivational suffixes on producing new words with distinct grammatical functions highlights their importance in forming language and vocabulary.