listen vs hearken

listen and hearken both are verbs.

Word	Noun	Adjective	Verb	Adverb
listen	No	No	Yes	No
hearken	No	No	Yes	No

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

Other hyponyms of listen include hear out, listen in, advert, attend, give ear, hang, pay heed, hark, harken, eavesdrop, listen in.

listen (verb)	hearken (verb)
hear with intention	listen; used mostly in the imperative
listen and pay attention
pay close attention to; give heed to