Is y at the end of muddy derivational
The suffix in the word muddy is -y, which is an adjective-forming suffix usually added to nouns and verbs. The root word in muddy is mud.
'Inflectional morphemes' are ones that don't change the part of speech of a word, for instance, the plural suffix -s or the past tense marker -ed:
- bag → bags (both are nouns)
- want → wants, wanted (all of them are verbs)
'Derivational morphemes' on the other hand are ones that do change the part of speech of a word. For example, suffixes like -y, -ise/-ize etc:
- mud (noun) → muddy (adj)
- standard (noun or adj) → standardise (verb)