What is the term for an addition to the end of a word that changes its meaning?

A suffix is a linguistic addition that is attached to the end of a word to modify its meaning or grammatical function. For example, adding "-ness" to the adjective "happy" transforms it into "happiness," turning it into a noun. This process shifts the meaning and shifts the context in which the word can be used within sentences.

Suffixes often indicate tense, number, or grammatical aspects such as forming plurals or gerunds. Understanding suffixes is essential for building vocabulary and enhancing language comprehension, as they can provide critical information about the relationships between words and their functions. This is why the answer is correctly identified as a suffix, as it specifically refers to an addition at the end of a word, unlike prefixes that appear at the beginning or roots and stems that pertain to the base of words.