It's well known (and several past questions on this SE have covered) that to convert a two-syllable Latin-derived English verb into a noun, you shift the stress to the first syllable. This is apparently called "initial stress derivation". Some examples:
- permít (v.) ~ pérmit (n.)
- addréss (v.) ~ áddress (n.)
- recórd (v.) ~ récord (n.)
- expórt (v.) ~ éxport (n.)
However, I've just realized there's a class of verbs that obey a different rule: verbs ending in -use. When these verbs change into nouns, they keep the final-syllable stress, but devoice the final consonant: so the verb ends in /uz/, and its derivative ends in /us/.
- abuse: abú[z]e (v.) ~ abú[s]e (n.)
- diffuse: diffú[z]e (v.) ~ diffú[s]e (adj.)
- reuse: reú[z]e (v.) ~ reú[s]e (n.)
- excuse: excú[z]e (v.) ~ excú[s]e (n.)
My question: Why do verbs that end in "-use" follow this pattern rather than initial stress derivation?
(Or perhaps not strictly "rather than" - I can also think of one example that both shifts the stress and devoices the /z/:)
- refuse: refú[z]e (v.) ~ réfu[s]e (n.)