What does 'affix' mean in the context of morphology?

In the context of morphology, 'affix' refers specifically to elements such as prefixes and suffixes that are attached to a base word or root. By adding an affix to a root, it modifies the meaning of the word or alters its grammatical function. For example, adding the prefix 'un-' to the root 'happy' creates the new word 'unhappy,' which has an opposite meaning. Similarly, adding the suffix '-ing' to a verb can change its tense or form, as in 'dance' becoming 'dancing.' This process of adding affixes is crucial for understanding how words are constructed and how their meanings can change based on their morphological components.

The other options describe different concepts but do not accurately define 'affix' in the morphological sense. A compound word, for instance, involves combining two separate roots rather than adding an affix. Standalone words that convey meaning fall outside the definition of an affix, and grammatical errors pertain to misuse of language rather than morphological structure. Thus, the definition of 'affix' as a prefix or suffix that modifies a root is essential for grasping the basics of morphology.