What do derivational suffixes do to a base word or root?

Derivational suffixes play a crucial role in the transformation of base words or roots by altering their part of speech or function. When a derivational suffix is added to a base word, it can change the grammatical category of that word. For example, adding the suffix "-er" to the verb "teach" forms the noun "teacher," thus changing the function of the word from a verb to a noun. Similarly, adding "-ly" to the adjective "quick" creates the adverb "quickly," shifting the part of speech again from an adjective to an adverb. This characteristic of derivational suffixes is essential for expanding vocabulary and understanding language structure, as they enable words to be used in different contexts with varying meanings.

Other options, such as those involving changes in pronunciation, the formation of compound words, or adding emphasis, do not accurately reflect the primary function of derivational suffixes. While pronunciation may sometimes be affected by the addition of certain suffixes or prefixes, this is not a defining feature of derivational suffixes. Likewise, the creation of compound words involves combining two independent words rather than modifying a base word with a suffix. Adding emphasis typically does not relate to the role of derivational suffixes, as their purpose