accent vs emphasize

accent is a noun but emphasize is not a noun.

Word	Noun	Adjective	Verb	Adverb
accent	Yes	No	Yes	No
emphasize	No	No	Yes	No

As verbs, accent and emphasize are synonyms defined as:

Other synonyms of accent include accentuate, emphasise, punctuate, stress.

As verbs, emphasize is a hyponym of accent; that is, emphasize is a word with a more specific, narrower meaning than accent:

accent (noun)	emphasize (noun)
the relative prominence of a syllable or musical note (especially with regard to stress or pitch)
distinctive manner of oral expression
a diacritical mark used to indicate stress or placed above a vowel to indicate a special pronunciation
the usage or vocabulary that is characteristic of a specific group of people
special importance or significance

accent (verb)	emphasize (verb)
put stress on; utter with an accent	to stress, single out as important
to stress, single out as important	give extra weight to (a communication)